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[Radio]Skyrocket Radio Thread

Here are cwm zips for the radios we have available at this time(that work). These will work for both the AT&T Skyrocket and the Rogers Skyrocket, take your pick I will be updating this thread as new radios become available. Please do not ask for the Japanese SC03DDCMKK3 radio, it does not work properly with our device.
Included in these zips:
mdm.bin
amss.bin
RIL
How To Flash:
Install with clockworkmod like you would any other zip.
I have tested these myself, as well as others on IRC and they have worked fine. I am not responsible if something goes wrong for you.
1. Original Shipped AT&T Skyrocket Radio I727ATTKJ2 and RIL
This is the radio that shipped with the AT&T Skyrocket, it is RAT interface locked which means you can't change bands by dialing *#2263#*
Click to expand...
Click to collapse
2. Original Shipped Rogers I727RUXKJ7 Radio and RIL
This is the radio that shipped with the Canadian Rogers version of Skyrocket, it is not RAT locked and bands can be changed easily by dialing *#2263#*
Click to expand...
Click to collapse
3. AT&T 2.3.6 OTA Update Radio I727ATTKK1 and RIL
This radio is also RAT locked
Click to expand...
Click to collapse

If anyone has flashed the AT&T 2.3.6 update, please pm me and I will walk you through extracting the radio so others can flash it

have tried it and it works!!!!!!!!!!!

awesome! would love to flash kk1 radio and get 2.3.6 and up.
Sent from my SGH-I727 using xda premium

twopumpchump said:
If anyone has flashed the AT&T 2.3.6 update, please pm me and I will walk you through extracting the radio so others can flash it
Click to expand...
Click to collapse
So you mean that once we flash to the 2.3.6, we can't just go back to .5?

latinohot said:
So you mean that once we flash to the 2.3.6, we can't just go back to .5?
Click to expand...
Click to collapse
why would you think i meant that lol...I need someone who has already flashed the 2.3.6 update to extract the radio from their device and send it to me so i can make cwm zips for everyone else to try Using this method to flash radios there is no verification check for upgrade/downgrade, so you can flash them back and forth all you want.

Thanks for doing this!!! I ended up going out after work so didn't get to it like I planned. If you don't mind I'll just link to this thread but you'll probably be stick-ied too. TA.

InSaiyanone said:
Thanks for doing this!!! I ended up going out after work so didn't get to it like I planned. If you don't mind I'll just link to this thread but you'll probably be stick-ied too. TA.
Click to expand...
Click to collapse
Your welcome, and if it needs to be stickied say the word...I can do that myself hehe.

I flashed nandroid to 2.3.6 so I have it available if needed.
Edit: Well after further investigation I read that nandroid back-up does not contain radio...so, oops
Sent from my SAMSUNG-SGH-I727 using XDA App

Thanks. Finally able to update my radio. Much appreciated for the effort.

For AT&T, which radio has the best reception in you're opinion...
Sent via rooted SkyRocket

After much testing, the current selection of radios seem to offer no difference in performance, the major difference is that the Rogers radio is RAT unrestricted vs. RAT restricted AT&T radio, which allows you to type "*#2263#" in the dialer and set the phone to 2g only, 3g only, 4g only, etc.

Da_G said:
After much testing, the current selection of radios seem to offer no difference in performance, the major difference is that the Rogers radio is RAT unrestricted vs. RAT restricted AT&T radio, which allows you to type "*#2263#" in the dialer and set the phone to 2g only, 3g only, 4g only, etc.
Click to expand...
Click to collapse
Ok... so I totally managed to **** something.
Picked a band, and I can't get signal anymore. Reflashed TPC v3, nothing. New modem, nothing...
Crap.
---------- Post added at 03:05 PM ---------- Previous post was at 02:59 PM ----------
Longcat14 said:
Ok... so I totally managed to **** something.
Picked a band, and I can't get signal anymore. Reflashed TPC v3, nothing. New modem, nothing...
Crap.
Click to expand...
Click to collapse
FIXED IT! Apparently taking out my SIM card and putting it back in fixed it.

I'm running KK1 and can dd a partition if that's what you need. PM me or message me on irondust(lart).

Hey, noob question but whats the point of flashing this radio lol? Does this actually allow you to use the radio that the skyrocket was supposed to come with but doesnt have an app for?

These are the firmware that control the Cellular Radio, DSP (Digital Signal Processor) and various bootloaders, not the FM radio that may or may not be part of our bluetooth chipset
BTW, AT&T 2.3.6 KK1 radio coming up shortly courtesy of lart, I'm just packaging it up now

Thanks for the fast apply, I appreciate it =) I wish we could get the radio to work on the phone if it really is built in

Did anyone take close up photos of our motherboard yet?
There are various FM radio drivers contained in the kernel, but all of them are disabled @ stock config. No idea if the chip is actually present or not, or if it is, if it's physically wired to the headphone jack (FM radio uses headphone cord as antenna generally speaking)
Close up pics of the motherboard would tell us if it's there or not

I just tried out the rogers radio (I am on ATT) and I was getting extremely low data speeds on EDGE, UMTS, and HSPA+ (10kBps) (tried both phone and PTA apns). Making calls worked fine though.

Flashed the radio and am playing around with the bands using 2263, looks like I can force EDGE by selecting GSM (I assume we should select the 850/1900 for AT&T) and can force hspa by selecting the WCDMA)
How would I force it into 3G only mode, (UMTS?)

N900W8 New firmware

New update for my fellow Canadian's and anyone with a N900W8. Here is a firmware update (finally) new version N900W8VLUCNI1 it is for Vidotron, but has all canadian carries csc info. http://www.sammobile.com/firmwares/3/?download=34884

Anyone try the new Modem NI1 Modem yet for our phones? Im on NC3 and was thinking of going back to NB7 but came across this off sam mobile as well.
nvm, updated it anyway and so far have a lot better signal then i did before

djtiko said:
Anyone try the new Modem NI1 Modem yet for our phones? Im on NC3 and was thinking of going back to NB7 but came across this off sam mobile as well.
nvm, updated it anyway and so far have a lot better signal then i did before
Click to expand...
Click to collapse
How did you update? Just Odin the NI1 file? I'm curious as to if people who aren't running a Note 3 on Videotron can Odin without issues.

Yup, I just Odin the ni1 modem file and I was good to go I'm on wind mobile and no issues so far
Sent from my SM-N900W8 using XDA Premium 4 mobile app

djtiko said:
Yup, I just Odin the ni1 modem file and I was good to go I'm on wind mobile and no issues so far
Sent from my SM-N900W8 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
Nice! I'll have to try it out! Any noticeable differences? Better battery life?

djtiko said:
Anyone try the new Modem NI1 Modem yet for our phones? Im on NC3 and was thinking of going back to NB7 but came across this off sam mobile as well.
nvm, updated it anyway and so far have a lot better signal then i did before
Click to expand...
Click to collapse
Do you get LTE on NI1; it seems that I don't anymore

I'm on wind and they don't support LTE so I'm not sure
Sent from my SM-N900W8 using XDA Premium 4 mobile app

Anyone try new modem with Rogers?
Curious if any difference.
---------- Post added at 06:07 PM ---------- Previous post was at 06:07 PM ----------
DrawnToLife said:
Do you get LTE on NI1; it seems that I don't anymore
Click to expand...
Click to collapse
Who is your provider?

fidorulz said:
Anyone try new modem with Rogers?
Curious if any difference.
---------- Post added at 06:07 PM ---------- Previous post was at 06:07 PM ----------
Who is your provider?
Click to expand...
Click to collapse
I'm on Rogers. I actually don't know if I don't have LTE, or if the region I'm currently living in just has terrible LTE support since my friends don't have LTE here either (and I'm sure like, none of them have flash an.. anything).

DrawnToLife said:
I'm on Rogers. I actually don't know if I don't have LTE, or if the region I'm currently living in just has terrible LTE support since my friends don't have LTE here either (and I'm sure like, none of them have flash an.. anything).
Click to expand...
Click to collapse
You're probably in a region without LTE ... I'm getting LTE without any problem on Vidéotron (with my LTE sim) and my wife's sim on Fido...
Envoyé de mon SM-N900W8 en utilisant Tapatalk

zadigre said:
You're probably in a region without LTE ... I'm getting LTE without any problem on Vidéotron (with my LTE sim) and my wife's sim on Fido...
Envoyé de mon SM-N900W8 en utilisant Tapatalk
Click to expand...
Click to collapse
Well, I'm in Waterloo right now. But yeah no, I actually do get LTE; it's just this area has terrible coverage.

Difference after update
Hi,
Can you post some noticeable difference after the update?
- any new apps?
- any updated apps?
- I read there is some new added functionality or feature added to S-Cover? Is it true?
Thanks

djtiko said:
Yup, I just Odin the ni1 modem file and I was good to go I'm on wind mobile and no issues so far
Sent from my SM-N900W8 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
How did you update the modem to NI1? I Odined the modem.bin file, but my baseband is still NB7..

Any mirror links? That site is always horribly slow and prone to failed downloads all the time.

skadude66 said:
How did you update the modem to NI1? I Odined the modem.bin file, but my baseband is still NB7..
Click to expand...
Click to collapse
You have to turn off your device ... Not just reboot to download mode.
If you just reboot to download mode, modem partition will be protected... If you turn off your device before going into download mode, you will be fine. I even removed the battery to make sure it was really off.
Sent from my Galaxy NOTEPRO 12.2

djtiko said:
Yup, I just Odin the ni1 modem file and I was good to go I'm on wind mobile and no issues so far
Sent from my SM-N900W8 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
Would you happen to have the modem file to flash via Odin?

zadigre said:
You have to turn off your device ... Not just reboot to download mode.
If you just reboot to download mode, modem partition will be protected... If you turn off your device before going into download mode, you will be fine. I even removed the battery to make sure it was really off.
Sent from my Galaxy NOTEPRO 12.2
Click to expand...
Click to collapse
Awesome, it worked! Thanks!!

fidorulz said:
Would you happen to have the modem file to flash via Odin?
Click to expand...
Click to collapse
skadude66 said:
Awesome, it worked! Thanks!!
Click to expand...
Click to collapse
Well I'm at work right now but I can try and post it up later.
Also yeah I do it the same way. Turn phone off. Pull battery. Put it back it and boot to download mode.
Glad it worked!
Sent from my SM-N900W8 using XDA Premium 4 mobile app

DrawnToLife said:
I'm on Rogers. I actually don't know if I don't have LTE, or if the region I'm currently living in just has terrible LTE support since my friends don't have LTE here either (and I'm sure like, none of them have flash an.. anything).
Click to expand...
Click to collapse
Here are the files
https://www.androidfilehost.com/?fid=23622183712473974
Tested modem on Rogers Note 3 using Fido SIM in Montreal and LTE works fine
WIll test for a while to see if better or not vs last Bell/Rogers/Telus modem N900W8VLUCNB7

fidorulz said:
Here are the files
https://www.androidfilehost.com/?fid=23622183712473974
Tested modem on Rogers Note 3 using Fido SIM in Montreal and LTE works fine
WIll test for a while to see if better or not vs last Bell/Rogers/Telus modem N900W8VLUCNB7
Click to expand...
Click to collapse
No idea if it it's any better than NB7, but I'm definitely getting LTE. Must have been the building I was in when I flashed.
Sent from my SM-N900W8 using XDA Free mobile app

Modem 4.4.2 I337MUMUFOA1 TTT

Modem + NON-HILOS
Extract rar/zip file
Flash with Odin. You may need to flash it twice.
Enjoy.
OA1 modem:
https://mega.nz/#!L45klT7S!ZmpO-NwadNrYgMsYgd0kRpCmneLLeLBSturkt-a-rFI
NK1 modem:
https://mega.co.nz/#!HlJXkSIK!RB93ncfZFBACZYfqc72wz-9FWx4lFg30d4sPcWvJ0NI
NI2 modem:
https://mega.co.nz/#!i4BFBTIb!14g7fp8lph0j5T4sfz1AHSChuZqTFUz8V00se0Fqn7s

Where did this come from? Anyone test on Rogers?

cantenna said:
Where did this come from? Anyone test on Rogers?
Click to expand...
Click to collapse
Apparently this version of the firmware was released for Telus/Koodo/Bell/Virgin on Sept 29 per SamMobile. I would assume that a Rogers version should be release shortly.
I have a Telus I337M but waiting for some feedback prior to flashing. I am currently on VLUFNE1 bootloader running UMUFNI1 modem.

Yes, I'm on NI1 as well, thanks

liquidzyklon said:
Apparently this version of the firmware was released for Telus/Koodo/Bell/Virgin on Sept 29 per SamMobile. I would assume that a Rogers version should be release shortly.
I have a Telus I337M but waiting for some feedback prior to flashing. I am currently on VLUFNE1 bootloader running UMUFNI1 modem.
Click to expand...
Click to collapse
This is a multi-csc rom. I flashed it and changed its csc to fido.
Sent from my SGH-I337M using Tapatalk

ma678 said:
This is a multi-csc rom. I flashed it and changed its csc to fido.
Sent from my SGH-I337M using Tapatalk
Click to expand...
Click to collapse
There all multi-csc aren't they? Just asking cause its the first time I heard this term.
So it should work with Rogers. I'll give it a try later this afternoon

cantenna said:
There all multi-csc aren't they? Just asking cause its the first time I heard this term.
So it should work with Rogers. I'll give it a try later this afternoon
Click to expand...
Click to collapse
The modem definitely works with Rogers.
The NI2 rom has all Canadian GSM carriers and quite a few more carriers. By default it flashes Bell. I tried Telus and then stick with Fido.
Sent from my SGH-I337M using Tapatalk

Confirmed Working fine here with MDJ & NH1 bootloader Rogers network

liquidzyklon said:
Apparently this version of the firmware was released for Telus/Koodo/Bell/Virgin on Sept 29 per SamMobile. I would assume that a Rogers version should be release shortly.
I have a Telus I337M but waiting for some feedback prior to flashing. I am currently on VLUFNE1 bootloader running UMUFNI1 modem.
Click to expand...
Click to collapse
Bootloader = VLUFNE1
Modem = VLUFNI2
Non-HILOS = VLUFNI2
Working well, no improvements compared to UMUFNI1 or UMUFNE3. The dBm readings are about the same, but at least this is the official Canadian modem.

ma678 said:
This is a multi-csc rom. I flashed it and changed its csc to fido.
Sent from my SGH-I337M using Tapatalk
Click to expand...
Click to collapse
My friend how you changed the CSC ???

Dial *#272*imei# on your keypad.
omek07 said:
My friend how you changed the CSC ???
Click to expand...
Click to collapse

if not better is it stable-er?
Im on a 337m that I picked up used and was on ne1.
So anyway I gave it a few days on stock- cell n data worked fine. Im actually getting up to 15 mbps on wind, wow. Tried goldfinger rom by ibastid and great but lacking some stuff I was used to like the tw refusing to rotate. Tried hyperdrive and wow feature rich. but I lose signal every now n then or upon a reboot. Like randomly once a day or so, toggling flight mode gets it back instantly. But modem issue yall think? Dont know if there is something I can tweak in ktoonzez

Loosing signal every so often, that's because your on wind network. I used to be o. Wind network as well and had this issue. Went away after switching to Rogers.

Rogers/Fido firmware was also updated last night. Basically they are all the same, though.
liquidzyklon said:
Apparently this version of the firmware was released for Telus/Koodo/Bell/Virgin on Sept 29 per SamMobile. I would assume that a Rogers version should be release shortly.
I have a Telus I337M but waiting for some feedback prior to flashing. I am currently on VLUFNE1 bootloader running UMUFNI1 modem.
Click to expand...
Click to collapse
cantenna said:
Where did this come from? Anyone test on Rogers?
Click to expand...
Click to collapse
cantenna said:
Loosing signal every so often, that's because your on wind network. I used to be o. Wind network as well and had this issue. Went away after switching to Rogers.
Click to expand...
Click to collapse

Can not enable WiFi
I have rooted Fido Samsung Galaxy S4. Today I have updated it to NI2 firmware using Kies3.
When update finished, my modem was still showing NE1 and WiFi did not work.
I flashed NI2 model file (from the first post) using Odin.
Now both Firmware and baseband version show NI2, however WiFi is still disabled and I can not get it to work.
Already tried to to reflash NI2 modem with Odin for a few times, but it does not solve the problem.
Could someone please help me to solve this issue ?
Thanks!

Why would u update using kies?

fmark said:
I have rooted Fido Samsung Galaxy S4. Today I have updated it to NI2 firmware using Kies3.
When update finished, my modem was still showing NE1 and WiFi did not work.
I flashed NI2 model file (from the first post) using Odin.
Now both Firmware and baseband version show NI2, however WiFi is still disabled and I can not get it to work.
Already tried to to reflash NI2 modem with Odin for a few times, but it does not solve the problem.
Could someone please help me to solve this issue ?
Thanks!
Click to expand...
Click to collapse
I had the same problem after upgrade. Here is what I did.
Odin the full rom. Downgrade modem following the website:
http://www.w0lfdroid.com/2014/09/To...-and-Note3-Android-4.4.2-NF-or-Later.html?m=1
Root phone with TowelRoot. Install SuperSu and twrp recovery. Odin back NI2 modem. Install a customized kernel. I tested Adam and Alucard working on wifi.
Note: you will probably have to turn off Smart Connect to keep wifi staying. Try it first before you start to Odin the stock firmware.
Good luck.
Sent from my SGH-I337M using Tapatalk

Thanks! In the end I just backed everything up with Titanium and did hard reset and then restore. Now WiFi works.

anyone got changelog for new update

nabbasi said:
anyone got changelog for new update
Click to expand...
Click to collapse
All I've read online is that Google Play Services have been updated. And this Play Services update really does a number on the battery life. I haven't installed it yet, can't seem to find much info about this update.

g930w8 - mistakenly given?

I am with Rogers in Canada and was upgrading my plan that included a good deal on a s7 if I wanted it - they dropped the phone off at my office but I believe it's the Bell version - is that correct SM-G930W8? I've not opened the box as I plan to sell it - should I ask for the Rogers version, is it better for some reason? Thanks
Sorry, I'm a Nexus guy, don't know the Samsung phones really at all

w8 is the canadian version, when you pop in a carriers sim it'll download their appropriate bloatware.

SM-G930W8 - Canadian Note 7 (all carriers have the same phone).
Sent from my SM-G930W8 using Tapatalk

peachpuff said:
w8 is the canadian version, when you pop in a carriers sim it'll download their appropriate bloatware.
Click to expand...
Click to collapse
And am I limited in which ROMs I could run on this? Might be selling to a guy at work and he's never done such a thing..

gribbler said:
And am I limited in which ROMs I could run on this? Might be selling to a guy at work and he's never done such a thing..
Click to expand...
Click to collapse
Kinda, but im sure if you flash a w8 kernel the rom will work since all the roms are made for exynos. Your other option is the 930f which is the international version, but that's no reason to get rid of the w8.

I am using Telus version SM G930w8 in Pakistan, will I get updates on it?

Sheikha said:
I am using Telus version SM G930w8 in Pakistan, will I get updates on it?
Click to expand...
Click to collapse
Probably not pushed no but you can easily update through Smart switch.
Sent from my SM-G930W8 using XDA-Developers mobile app
---------- Post added at 04:16 AM ---------- Previous post was at 04:15 AM ----------
gribbler said:
And am I limited in which ROMs I could run on this? Might be selling to a guy at work and he's never done such a thing..
Click to expand...
Click to collapse
AFAIK all 930F roms work on the w8, even if I only rooted on stock rom myself.
Sent from my SM-G930W8 using XDA-Developers mobile app

Thanks. Hot to check if the last update was via OTA or Kies? Pls help

Verizon LG-V20 (VS995) Poor network on T-Mobile = Verizon firmware restrictions?

Hi everyone,
I just switched over to T-Mobile and the first thing I noticed is that my LGV20(VS995) was not properly connecting to the T-Mobile network, I tried every possible APN setting and the connection was always unstable. Sometimes I briefly got an 4G LTE signal but when I ran countless tests and the connection speeds were always below 10mbps.
I recently flashed the Lineage OS on my phone to check if it was possibly a Verizon firmware restriction and I found that as soon as the phone booted with the Lineage OS, the phone recognized the sim card as T-Mobile, and right off the bat, the phone connected to LG LTE. I ran network tests using Ookla's Speed Test apk, and now I get consistent speeds over 30mbps, highest being nearly 90mbps. (tests were done using same server and in the same area)
My question is,
is there some sort of network band restriction embedded in the Verizon firmware? and is there a workaround for this on stock Verizon firmware?

I was havong this problem with my ls997 can this lineage OS work on my ls997?
Sent from my LG-LS997 using Tapatalk
---------- Post added at 03:27 AM ---------- Previous post was at 03:18 AM ----------
Do u have a link to the os ??
Sent from my LG-LS997 using Tapatalk

bikermites said:
I was havong this problem with my ls997 can this lineage OS work on my ls997?
Sent from my LG-LS997 using Tapatalk
---------- Post added at 03:27 AM ---------- Previous post was at 03:18 AM ----------
Do u have a link to the os ??
Click to expand...
Click to collapse
The LS997 is currently supported, however, this ROM is currently in its alpha stages. I've been using it daily and thus far it's stable.
Here's the link, assuming you have already unlocked the bootloader and rooted your phone:
https://forum.xda-developers.com/v20/development/dev-cm14-t3509953

I had a similar situation with AT&T sim card in the vs995. I would get temporary lte connection then back to H. I assumed I had a weak band 4 connection but maybe I'll try that rom & see if it helps.

ajent said:
I had a similar situation with AT&T sim card in the vs995. I would get temporary lte connection then back to H. I assumed I had a weak band 4 connection but maybe I'll try that rom & see if it helps.
Click to expand...
Click to collapse
If u get through please let me know
Sent from my LG-LS997 using Tapatalk

I'm about to try in a bit too.Finally got abd figured out .I will let you know..I have vzw v20 and wanting it on tmo
Sent from my Nexus 6P using Tapatalk

Ok
Sent from my LG-LS997 using Tapatalk

After installing the rom, it gave me the sim card not found error, flashed gapps and lte internet worked, but couldn't text or call. Tried to restore my backup, but it wouldnt let me log into phone with fingerprint, and told me my pin was wrong. Installing not so stock rom now.

Ok
Sent from my LG-LS997 using Tapatalk

ajent said:
After installing the rom, it gave me the sim card not found error, flashed gapps and lte internet worked, but couldn't text or call. Tried to restore my backup, but it wouldnt let me log into phone with fingerprint, and told me my pin was wrong. Installing not so stock rom now.
Click to expand...
Click to collapse
@ajent
Did you install the latest 7.1 gaps, ARM64bit?
When you go to the site select 7.1 gaps, ARM64bit (LGV20 runs on ARM64bit) & and stock. You have to install both back to back before booting up.
Do not wipe system prior to installation as lineage OS patches the system. only wipe data, cache, and dalvik.
Also in settings go to APN and check if what APN preset you have selected, the ROM comes with presets for all carriers.
Those are the 3 things that I can think of that would cause those issues.
Everything works fine for me besides the second screen at the top and Bluetooth. I haven't noticed anything else so far, I've had Lineage OS installed since 01/13.

Gapps selection for LGV20

Did you flash the Verizon version,or T-Mobile verson
Sent from my VS995 using Tapatalk

kenbrownstone said:
Did you flash the Verizon version,or T-Mobile verson
Click to expand...
Click to collapse
I flashed the one for Verizon (vs995)

lightX87 said:
I flashed the one for Verizon (vs995)
Click to expand...
Click to collapse
You on t mobile?
Sent from my VS995 using Tapatalk
---------- Post added at 01:03 AM ---------- Previous post was at 01:00 AM ----------
lightX87 said:
I flashed the one for Verizon (vs995)
Click to expand...
Click to collapse
Sorry forgot you were the o.o..thanks for thread
kenbrownstone said:
You on t mobile?
Sent from my VS995 using Tapatalk
Click to expand...
Click to collapse
Sent from my VS995 using Tapatalk

kenbrownstone said:
You on t mobile?
Sent from my VS995 using Tapatalk
---------- Post added at 01:03 AM ---------- Previous post was at 01:00 AM ----------
Sorry forgot you were the o.o..thanks for thread
Click to expand...
Click to collapse
No prob , anytime!
And yes, just switched to Tmobile since Verizon took away my unlimited data and I wasn't even near the 200 gigs..

Did u try to register the device on the tmobile network on the stock firmware via network settings?

Mikekelso421 said:
Did u try to register the device on the tmobile network on the stock firmware via network settings?
Click to expand...
Click to collapse
As mentioned in OP, I tried a combination of APN settings, and yes, I tried to register the phone manually and auto.
When I registered the phone to T-Mobile LTE and the phone connects to LTE for a brief moment and goes back to switching from 3G and H+. And even when it's on "4G" the network speeds are unstable.
I noticed I wasn't the only one having this issue when switching networks from Verizon to Tmobile so I rooted the phone and installed the Not so Stock ROM and still had the same results, then I searched for a custom ROM and found Lineage OS (thank God) I installed it and right away after booting, the phone recognized the T-Mobile simcard; as apposed to stock, where it kept giving me a notification saying Verizon simcard not found even when registered to T-Mobile

if you install the US996 Rom its pretty much stock rom with LTE working. I would recommend it with the konvergence kernel because well thats really the only one I think that makes our phone boot with that rom.

When you buy a carrier branded phone it comes with certain bands activated for that network with the others disabled. While this is done at a software level, it is done on a partition and files not even remotely controlled by the ROM. Likely your bands are locked behind some level of encryption that you would need special software to unlock. IF it isn't hardware locked (which is highly unlikely since this is a global phone).
tl;dr If you want to use non-common LTE bands (2,4,etc) for other carriers you need that carrier's device or an actual unlocked device.

Actually this has been solved by installing ported firmware based on the international version of LGV20 or lineage OS. I have a constant 4G connection with MMS and calls properly functioning. Even though the verizon phones are global, at software level, certain bands/network settings are indeed restricted.