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Anyone using a non-AT&T 8X on AT&T?

Is anyone here using a non-AT&T branded HTC 8X on AT&T with everything working on 2G and 3G? I don't care about 4G for this particular case.
Does Voice, SMS, MMS in both directions, and data work?
Does AT&T detect it as a smartphone and require the right data plan?
Thanks.
Edit: I decided to buy both a Verizon 8X and a T-Mobile 8X to test.
After 4 days the Verizon was detected
T-Mobile one has still not been detected. Will update if it does.

petard said:
Is anyone here using a non-AT&T branded HTC 8X on AT&T with everything working on 2G and 3G? I don't care about 4G for this particular case.
Does Voice, SMS, MMS in both directions, and data work?
Does AT&T detect it as a smartphone and require the right data plan?
Thanks.
Click to expand...
Click to collapse
I'm pretty sure you would be able to get 3G with any unlocked 8X but only certain models have LTE radios. You will probably need to add an APN to get you're Data/MMS working 100% and I at least had an issue with tethering (not sure if it is hardware or software related) but other than that you should be golden.
Although obvious, I may as well say it. It should be an unlocked phone.

I'm asking for people with personal experience because Windows Phone is such a pain with APN configuration. I have tried a couple unlocked Verizon phones but they won't work with MMS no matter what I do. There is the generic unbranded GSM version, but that one is expensive compared to the branded ones. Also people are complaining that that HTC connection setup utility is broken on the 8X so I would just really like to know if anyone has actually tested it. I don't want to get the AT&T version because they recognize that one and require a data plan and I don't want one on this line.

petard said:
I'm asking for people with personal experience because Windows Phone is such a pain with APN configuration. I have tried a couple unlocked Verizon phones but they won't work with MMS no matter what I do. There is the generic unbranded GSM version, but that one is expensive compared to the branded ones. Also people are complaining that that HTC connection setup utility is broken on the 8X so I would just really like to know if anyone has actually tested it. I don't want to get the AT&T version because they recognize that one and require a data plan and I don't want one on this line.
Click to expand...
Click to collapse
Well, ummm, I am talking about personal experience and those are my experiences. What more specifically would you like to know?
BTW, adding the APN is extremely easy if you know how...

mobi said:
Well, ummm, I am talking about personal experience and those are my experiences. What more specifically would you like to know?
BTW, adding the APN is extremely easy if you know how...
Click to expand...
Click to collapse
Does Voice, SMS, MMS in both directions, and data work?
Does AT&T detect it as a smartphone and require the right data plan?
Which version of the phone are you using? International unbranded?

petard said:
Does Voice, SMS, MMS in both directions, and data work?
Does AT&T detect it as a smartphone and require the right data plan?
Which version of the phone are you using? International unbranded?
Click to expand...
Click to collapse
Yes. Voice, SMS, MMS and data worked fine. AT&T see it just fine and actually, you will probably see it listed in MyATT after you put the SIM in.
My phone is a C625a which has LTE however, an international unlocked version or a Verizon version will work but only certain models will get LTE because of the radios as mentioned above.

mobi said:
Yes. Voice, SMS, MMS and data worked fine. AT&T see it just fine and actually, you will probably see it listed in MyATT after you put the SIM in.
My phone is a C625a which has LTE however, an international unlocked version or a Verizon version will work but only certain models will get LTE because of the radios as mentioned above.
Click to expand...
Click to collapse
Is your phone a non-AT&T 8X? Or is it the AT&T branded one?
They are detecting it as an 8X?
Like my thread title says, I want to know if anyone is using a non-AT&T branded 8X. I DO NOT want them to know what phone it is because if they recognize it then they will require a "correct" smartphone data plan which I do not want.
I tried a Verizon Lumia 822 but I could not get MMS to work at all. They even removed the internet and MMS apn configuration pages built into WP8. I could use the Nokia app for setting the APN, but even with the correct MMS settings incoming MMS would not work. Outgoing would work just fine and everything else worked.
I just want to know if anyone has a non-AT&T 8X where everything on 3G works and that AT&T doesn't detect it.

petard said:
Is your phone a non-AT&T 8X? Or is it the AT&T branded one?
They are detecting it as an 8X?
Like my thread title says, I want to know if anyone is using a non-AT&T branded 8X. I DO NOT want them to know what phone it is because if they recognize it then they will require a "correct" smartphone data plan which I do not want.
Click to expand...
Click to collapse
YES, non ATT

mobi said:
YES, non ATT
Click to expand...
Click to collapse
I'm sorry but you are very unclear. So your phone is NOT an AT&T branded 8X and they DO detect it as an 8X and require the smartphone data plan?

petard said:
I'm sorry but you are very unclear. So your phone is NOT an AT&T branded 8X and they DO detect it as an 8X and require the smartphone data plan?
Click to expand...
Click to collapse
You asked
petard said:
I want to know if anyone is using a non-AT&T branded 8X.
Click to expand...
Click to collapse
and I said yes, non ATT which means that it is a non AT&T phone. How else can I say it? It is a non ATT unlocked phone.

mobi said:
You asked and I said yes, non ATT which means that it is a non AT&T phone. How else can I say it? It is a non ATT unlocked phone.
Click to expand...
Click to collapse
In my original post I asked
Does AT&T detect it as a smartphone and require the right data plan?
Click to expand...
Click to collapse
You haven't clearly answered this. All of your answers were ambiguous whether you were answering "YES" to "is it non-AT&T branded" or if it was a response to "Does AT&T detect it as a smartphone and require the right data plan?"

petard said:
In my original post I asked
You haven't clearly answered this. All of your answers were ambiguous whether you were answering "YES" to "is it non-AT&T branded" or if it was a response to "Does AT&T detect it as a smartphone and require the right data plan?"
Click to expand...
Click to collapse
I give up... Maybe someone else can help you.

mobi said:
I give up... Maybe someone else can help you.
Click to expand...
Click to collapse
I'm sorry that my questions were too confusing for you.
Maybe having it in a list will make it easier for people to respond
Questions:
1. Do you have a non-AT&T branded HTC 8X
2. Does this HTC 8X work 100% with calls, SMS, MMS in both directions, and data connectivity on 3G
3. Does AT&T detect this as a smartphone (Which will force you to have a smartphone dataplan)?

petard said:
I'm sorry that my questions were too confusing for you.
Maybe having it in a list will make it easier for people to respond
Questions:
1. Do you have a non-AT&T branded HTC 8X
2. Does this HTC 8X work 100% with calls, SMS, MMS in both directions, and data connectivity on 3G
3. Does AT&T detect this as a smartphone (Which will force you to have a smartphone dataplan)?
Click to expand...
Click to collapse
3. Yes, as you're using a SIM card.

jValdron said:
3. Yes, as you're using a SIM card.
Click to expand...
Click to collapse
Simply using a SIM card does not mean AT&T knows what kind of phone it is. AT&T does not detect all smartphones as smartphones. They can detect all AT&T smartphones correctly and they have the ability to detect some non-AT&T smartphones, but not all. It's mostly the very popular unlocked models such as the Nexus models. Most other phones aren't in there database and just appear as unknown.
For instance they do not have the ability of detecting the ATIV S. I have one of those running on one of my lines with a $10 unlimited data plan. It doesn't support AT&T LTE, though, but that isn't an issue for the line it is on.
I would buy another ATIV S for this line, but it's too expensive at around $500. There are many 8Xs available for around $250 and I want to see if anyone is using any of those models without a correct data plan on AT&T.

mobi said:
I give up... Maybe someone else can help you.
Click to expand...
Click to collapse
Don't give up. Since you are the only one here did this. Go to your Myatt account page and see which phone is listed there for your line. If it listed as unknown or generic phone, it does not know you are using a Smartphone. If it listed as you are using a 8x, it means AT&T knows your phone is a smartphone. That's what OP wants.
As for OP, unlike WP7, WP8 lets you add data and MMS APNs easily.
jValdron said:
3. Yes, as you're using a SIM card.
Click to expand...
Click to collapse
That's non-sense.

foxbat121 said:
Don't give up. Since you are the only one here did this. Go to your Myatt account page and see which phone is listed there for your line. If it listed as unknown or generic phone, it does not know you are using a Smartphone. If it listed as you are using a 8x, it means AT&T knows your phone is a smartphone. That's what OP wants.
As for OP, unlike WP7, WP8 lets you add data and MMS APNs easily.
That's non-sense.
Click to expand...
Click to collapse
I ended up buying both a Tmobile 8X and a Verizon 8X. AT&T hasn't detected either and it's been 3 days. The Tmobile one fully works and the Verizon one can't send MMS.
Verizon removed the ability to set a MMS APN manually and the HTC Connection Setup app doesn't work on the Verizon one. It works on the Tmobile one but I believe it configures the phones using the Phone APN for both Internet and MMS. You don't have access to the Phone APN unless you have a smartphone data plan, but thankfully Tmobile didn't screw around too much with the firmware and I was able to manually enter the connection information for both Internet and MMS.

That was interesting. On AT&T 8x, you have two buttons, one to add data APN and one to add MMC APN.

foxbat121 said:
That was interesting. On AT&T 8x, you have two buttons, one to add data APN and one to add MMC APN.
Click to expand...
Click to collapse
Yeah the T-Mobile has both Internet and MMS APN options, but on Verizon the MMS APN option was removed with the Portico update and was present but didn't work (didn't save anything) before Portico.
The Verizon Lumia 822 had both internet and MMS options pre-portico and they both saved what was entered but post-portico they were both gone. Nokia has an APN configuration app though that works post-Portico. Unfortunately even with MMS configured the 822 just won't receive MMS. When an MMS comes in it says "Message not found". Sending MMS from the 822 works fine on AT&T though.
Basically Verizon ****s up MMS so you can't fully utilize a Verizon phone on a GSM carrier.
My T-Mobile 8X mic doesn't work when set to speakerphone though so I will need to get it replaced. I found a few people online with the same issue but they found no solution other than replacement.
The 8X is such a mess.

I guess Verizon will use its CDMA network to deliver MMS. So, it is a problem for them to expose the MMS settings for GSM which may hinder the MMS on CDMA network.

[Q] Verizon GS3 on NET10?

OK, so I am not an expert here but I know enough to give information that should help answer my question.
I have a Verizon (CDMA) Samsung Galaxy S3 (SCH-I535). I'd like to use this phone with a NET10 BYOD SIM card, but I'm not sure it will work. By all indications, my phone is a world phone that includes a GSM band. I say that because I can scan and attempt to connect to both AT&T and a local cell company that are both GSM services. In other words, I can select GSM/UMTS as a network option and it appears to work.
Trouble is, I don't have access to a GSM SIM, so there isn't any way for me to test this without spending money on the SIM card. SO in a round about way, I want to know if this will work. Can I buy a NET10 BYOD SIM, select GSM/UMTS under "Mobile Networks" in teh settings, and expect phone, text, and data to work?
I'm especially hoping to hear from people with the SCH-I535 Verizon GS3 if you've ever done this.
If this is not possible, is there any other BYOD SIM program that will allow for phone, text, and data in a CDMA Verizon phone? If so, what is it?
Thanks everyone.

If Verizon has not unlocked the phone off their carrier, then it will not work. (If you have the Jelly Bean Update, then its unlocked) If it is unlocked, then your in luck.
Mind you that I dont have this phone. But your phone is capable of ATT networks. Just avoid T-Mobile networks unless you want to be on EDGE.

Clarification
StatusQuo209 said:
If Verizon has not unlocked the phone off their carrier, then it will not work. (If you have the Jelly Bean Update, then its unlocked) If it is unlocked, then your in luck.
Mind you that I dont have this phone. But your phone is capable of ATT networks. Just avoid T-Mobile networks unless you want to be on EDGE.
Click to expand...
Click to collapse
Just to make sure I understand, if my phone is Android 4.1.2, then my phone is automatically unlocked and capable of use with an AT&T compatible SIM? And I suppose that includes the NET10 BYOD SIM, or the Straight Talk BYOD SIM for that matter?

How i Just do it con net 10 And is working but just edge .any suggestions settings to enable 4g ???
Sent from my XT910 using Tapatalk 4 Beta

bump
Hi - I am trying to do the same thing, did you have any success? If so, can I get the details of how you did it?
Thanks!!
amusso18 said:
Just to make sure I understand, if my phone is Android 4.1.2, then my phone is automatically unlocked and capable of use with an AT&T compatible SIM? And I suppose that includes the NET10 BYOD SIM, or the Straight Talk BYOD SIM for that matter?
Click to expand...
Click to collapse

Trying to do the same can anyone help me out?

Datdurtyboi said:
Trying to do the same can anyone help me out?
Click to expand...
Click to collapse
Did you check your song settings? Make sure you have your phone on global mode as well.

Locked

Bought this phone on ebay, later found out its face locked. Would rooting this then flash with a cooked rom make this phone usable ?

Reboot to bootloader and select "Factory".

kcipopnevets said:
Reboot to bootloader and select "Factory".
Click to expand...
Click to collapse
That dont work, its still locked.

Shining Light said:
That dont work, its still locked.
Click to expand...
Click to collapse
try this
http://forum.xda-developers.com/showthread.php?t=2580060

danger2u said:
try this
http://forum.xda-developers.com/showthread.php?t=2580060
Click to expand...
Click to collapse
This was my next suggestion, arrgh! Anyways, performing an FXZ will terminate existing root, and you will lose root permanently (as of now). Hopefully it's on Jelly Bean... Or you can try to continuously get the security lock wrong in an effort to cause it to factory reset. You'll at least still have the su binary still. Good luck!
Something else you can try before performing above... Reboot to bootloader, select "Recovery", and when you see the Android in distress, press and hold Vol + and then press and release Power to get the recovery menu options. Scroll down to "wipe data/factory reset" and let it do its thing.

Thanks for the help guys.
Im planning to root this and flash a cooked rom on it, whats the safest way to get rid of this face locked? (i def dont want to lose the ability to root it)
Whats the best cooked rom on here? Prefer something thats fast without overclocking and dont have too much pre-installed apps on it.
PS im gonna use this phone on att network, talk and txt should work fine right? Internet i know im not getting LTE i can live with that

Shining Light said:
Thanks for the help guys.
Im planning to root this and flash a cooked rom on it, whats the safest way to get rid of this face locked? (i def dont want to lose the ability to root it)
Whats the best cooked rom on here? Prefer something thats fast without overclocking and dont have too much pre-installed apps on it.
PS im gonna use this phone on att network, talk and txt should work fine right? Internet i know im not getting LTE i can live with that
Click to expand...
Click to collapse
You're stuck with the stock ROM (unless you can get a bootloader unlock code, which is only available for recently manufactured devices).
Unless you have LTE, the phone isn't going to work on AT&T. The Droid series is exclusive to Verizon, which uses CDMA technology for 3g service. AT&T uses GSM, and the phone doesn't have GSM radios.

@Shining Light You REALLY need to research these things before continuing on. It's unlikely you'll get unlocked so ROMs are out of the question for your case. Hopefully you're lucky and the bootloader unlock method opens again. Did you try asking the seller for their security past the face lock? If you revert to stock with RSD Lite, root will be a mere dream to you.

rlmesq said:
You're stuck with the stock ROM (unless you can get a bootloader unlock code, which is only available for recently manufactured devices).
Unless you have LTE, the phone isn't going to work on AT&T. The Droid series is exclusive to Verizon, which uses CDMA technology for 3g service. AT&T uses GSM, and the phone doesn't have GSM radios.
Click to expand...
Click to collapse
I think both the statements above are incorrect.
1. The bootloader unlock codes are actually not available for recently manufactured devices. Two of us have 1/10/2014 assembled devices and the unlock codes are unavailable with the seller. How recent should the devices be then?
2. I am using the same phone on GSM (though, outside US). So, the phone does have GSM bands supported. There are many who are using it on AT&T and T-mobile. Someone mentioned that the latest patch has disabled T-mobile network, but I suspect something else may have gone wrong in that case.

s_u_n said:
I think both the statements above are incorrect.
1. The bootloader unlock codes are actually not available for recently manufactured devices. Two of us have 1/10/2014 assembled devices and the unlock codes are unavailable with the seller. How recent should the devices be then?
2. I am using the same phone on GSM (though, outside US). So, the phone does have GSM bands supported. There are many who are using it on AT&T and T-mobile. Someone mentioned that the latest patch has disabled T-mobile network, but I suspect something else may have gone wrong in that case.
Click to expand...
Click to collapse
The chinese seller says that he has unlock codes for devices assembled in 2014 but some report that while their phones was assembled in 2014 - the unlock code was still not available - but, most of the time if the phone is build in 2014, there should be the code for it.
rlmesq said:
Unless you have LTE, the phone isn't going to work on AT&T. The Droid series is exclusive to Verizon, which uses CDMA technology for 3g service. AT&T uses GSM, and the phone doesn't have GSM radios.
Click to expand...
Click to collapse
WOW!!! This statement could not possible be any more wrong - DAMN! C'mon people, just google your anwer before posting!
Supported frequencies:
2G Network CDMA 800 / 1900
GSM 850 / 900 / 1800 / 1900
3G Network CDMA2000 1xEV-DO
HSDPA 850 / 900 / 1900 / 2100
4G Network LTE 700 MHz Class 13 / 1700 / 2100

N-920T & AT&T Data Issues

Is anyone using the T-Mobile Note 5 on AT&T? I am having data problems where I do not get data, but can send and receive texts, and also make calls. I switch to the Cingular APN and it works, but then goes out.
I have tried the Nxtgen phone apn and also phone apn, and no luck.

I know im not answering your question, but are you able to use the VOLTE feature on your tmobile phone on the at&t network? or even HD calling?

Actually At&t messed up my provisioning. You asked about those features, I would recommend you download Darthstalkers Rom Version 4, choose n9200A, it will install the at&t carrier files.
Just make sure to add the ATT Phone APN, do not use the nextgen phone apn.

Why do you suggest not using NextGen APN. I use it on all my phones and it's perfect your funny

I have been thinking of paying off my unrooted phone and switching to cricket. When I put my IME number to check compatibility it said it wasn't. So, I'm a bit confused. Is this phone compatible with ATT LTE or not. I thought that ATT and Cricket were the same?

sizz-lorr! said:
I have been thinking of paying off my unrooted phone and switching to cricket. When I put my IME number to check compatibility it said it wasn't. So, I'm a bit confused. Is this phone compatible with ATT LTE or not. I thought that ATT and Cricket were the same?
Click to expand...
Click to collapse
is your phone unlocked? if not you need to get your phone sim unlocked to get it to work on AT&T network. Im on AT&T and have no issues with data etc.

treoreloaded said:
is your phone unlocked? if not you need to get your phone sim unlocked to get it to work on AT&T network. Im on AT&T and have no issues with data etc.
Click to expand...
Click to collapse
No its not unloocked. But I will unlock it soon. Good to now that I can use it on ATT or cricket if I want. Really tired of Tmo.
Thanks.

Sprint HTC A9 Sim Unlock

Hello I have a Sprint HTC A9 that has been successful unlocked for domestic use, but I have voice with no data. I have S-Off, boot loader unlocked, running stock os. Has anyone else ran into this problem? Can someone please advise?

A friend mentioned that the Sprint variant might not have correct bands installed to be compat with other carriers. I'm wondering if replacing the radio firmware with the developer edition version would work, but I can't get around simlock to test.

HTC A9 Sprint Unlock success!!

Please share? I've been trying for days and made little progress.

There is a guy from Craigslist in my area that did it and he will not tell me, I asked. If there is any kind of way that I can back it up, screen shot it, or whatever. Someone please let me know. I don't have any personal data on it, because it has no data so I'm not using it yet. I don't care about sharing. Let me know and I'm more than happy to.

Devicerepair said:
There is a guy from Craigslist in my area that did it and he will not tell me, I asked. If there is any kind of way that I can back it up, screen shot it, or whatever. Someone please let me know. I don't have any personal data on it, because it has no data so I'm not using it yet. I don't care about sharing. Let me know and I'm more than happy to.
Click to expand...
Click to collapse
If it's an MSL code, he should have supplied that for you. I think MSL is unique to the IMEI/MEID/ESN of your device.
About your successful unlock, congrats! Your success let's me know it's do-able. I'm calling a local computer repair shop that offers unlocking services tomorrow. :fingerscrossed:

I've tried a half dozen ways to get this phone unlocked, but so far I've come up empty except for one scenario:
S-OFF
1. Change CID/MID to unlocked and flash unlocked RUU. Phone works fine, radio not functional.
2. Change CID/MID to sprint and flash sprint RUU. Phone will work with T-mobile SIM for one boot-up. As soon as phone is rebooted the SIM locks.
You can't just reflash the sprint RUU either. If you want to get another successful boot, you have to flash the unlocked RUU, then the sprint RUU and you'll get one boot. My only guess is something in the partitions is zero'd out by the unlocked RUU. I've also tried using the CM13 build immediately after the sprint RUU, and again I get one boot, but as soon as I reboot, CM13 shows sim not inserted.
Perhaps someone can make sense of this.

Attached screenshot proof unlock A9 Sprint, this unlock successfull :laugh:

Lussardi said:
Attached screenshot proof unlock A9 Sprint, this unlock successfull :laugh:
Click to expand...
Click to collapse
That not unlocked! I used mine in mexico to! Call sprint, they will unlock it for UMTS and HSP for free! Put a US AT&T sim in it and show me....
Cheers,
disco

disco_y2k said:
That not unlocked! I used mine in mexico to! Call sprint, they will unlock it for UMTS and HSP for free! Put a US AT&T sim in it and show me....
Cheers,
disco
Click to expand...
Click to collapse
i live in overseas and its worked for me :laugh::laugh::laugh:

Lussardi said:
i live in overseas and its worked for me :laugh::laugh::laugh:
Click to expand...
Click to collapse
which method you have used to unlock it?

hmmm.....I am seeing exactly the same thing. put in T-Mobile's sim card. the phone is working fine but no data. anybody got Sprint version of HTC A9 to work on GSM network?

scsc168 said:
hmmm.....I am seeing exactly the same thing. put in T-Mobile's sim card. the phone is working fine but no data. anybody got Sprint version of HTC A9 to work on GSM network?
Click to expand...
Click to collapse
put the correct APN and DATA works fine

Lussardi said:
put the correct APN and DATA works fine
Click to expand...
Click to collapse
Wow.... you are a life saver Lussardi! Thank you very much!
My HTC A9 has delivered APN setting, which cannot be modified. However, I was able to create a new APN manually and use that one. After that, data started to work. So far, I see it was able to connect to 4G and also LTE. At one place with strong LTE signal, i tested the download speed, and it was 82mbps. I have never seen that kind of download speed on my iPhone.
Thanks,
Sean

// , Did you unlock an HTC One A9 [Sprint] for complete LTE on T-Mobile or on AT&T?
// , Let me make sure I understand this correctly.
Can I do the following:
1. Unlock a Sprint HTC One A9.
2. Buy a data-enabled T-Mobile SIM card or AT&T SIM card.
3. Enter APN & Data settings.
4. Use that same HTC One A9 with T-Mobile or AT&T, with no loss in performance?
If this is true, that surprises and pleases me.
I assume that one can unlock an AT&T HTC One A9 for use with T-Mobile with no loss in performance, as well?
I found the following for my research about this question:
https://unlocklocks.com/blog/how-to-unlock-htc-one-a9-by-unlock-code/
http://forum.xda-developers.com/sitesearch.php?q=htc one a9 unlock
http://forum.xda-developers.com/one-a9/general/sim-unlock-free-help-to-help-t3307036

Adjutant said:
// , Let me make sure I understand this correctly.
Can I do the following:
1. Unlock a Sprint HTC One A9.
2. Buy a data-enabled T-Mobile SIM card or AT&T SIM card.
3. Enter APN & Data settings.
4. Use that same HTC One A9 with T-Mobile or AT&T, with no loss in performance?
If this is true, that surprises and pleases me.
I assume that one can unlock an AT&T HTC One A9 for use with T-Mobile with no loss in performance, as well?
I found the following for my research about this question:
https://unlocklocks.com/blog/how-to-unlock-htc-one-a9-by-unlock-code/
http://forum.xda-developers.com/sitesearch.php?q=htc one a9 unlock
http://forum.xda-developers.com/one-a9/general/sim-unlock-free-help-to-help-t3307036
Click to expand...
Click to collapse
My Sprint version of HTC A9 has been working on T-Mobile's network for almost a week now. I see no issues so far. Data connection is still good with connecting to LTE most of the time.

scsc168 said:
My Sprint version of HTC A9 has been working on T-Mobile's network for almost a week now. I see no issues so far. Data connection is still good with connecting to LTE most of the time.
Click to expand...
Click to collapse
What process did you go through? Can you provide a little more detail? Thanks...

motoelliot said:
What process did you go through? Can you provide a little more detail? Thanks...
Click to expand...
Click to collapse
i am not sure if my experience is any different from others here. but, here's the detail of what i went through....
My Sprint variant of HTC A9 was purchased directly off htc.com back in 11/2015. Since the phone was paid in full, I believe the phone was not locked to begin with. I had been using it on Sprint for the past 10 months. Just recently i switched my plan to T-Mobile. With T-Mobile's sim, I see the phone picked up the sim card. Phone started to work (i can make/receive calls) but data would not work. I talked to a couple of HTC rep for support. Both of them told me it should work. From their understanding, A9 and the new HTC 10 should work on all US major carriers...especially mine is a CDMA phone. According to them, CDMA ones can work on GSM....but GSM would not work on CDMA network. Anyways, they were no help for me.
I started doing research on my own and found many people experiencing the same. Phone would work but data would not connect. It was not working until a member on this board, Lussardi, came to rescue. He suggested to manually put in APN. So, I started to check out the APN setting. I see with t-mobile's sim card in, the phone is using a delivered T-Mobile APN setting. I went ahead and created one myself named T-Mobile Manual. I put in APN: fast.t-mobile.com and MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc and left everything else default. After I selected to use this new APN, the phone started to pick up mobile data. Now, depending on the area that i am in, i can see it's using either 4G or LTE. At one place with strong LTE signal, i did a speed test. It was over 80mbps.
Anyways, that's all. Good luck everyone.

// , Thank you!
// , Thanks for the thorough response, and for not just giving up.
The large corporations generally don't care too much about usability for this sort of outlier customer experience.

Can you give any instructions on how you unlocked the sprint version of the HTC A9?
Thanks.