Samsung A51 spontaneously losing mobile data connection - Samsung Galaxy A51 Questions & Answers

I have a peculiar issue with my Dual Sim Samsung A51 running Android 10. The phone status is official.
Usually about once per day (sometimes twice), the mobile data connection will switch off by itself, but its not going to off in the traditional / expected way which is the Mobile Data selector switch in Settings > Data Usage.
For some reason, the Data SIM selected in the Sim Card Manager will be lost (there are usually three options: Sim 1, Sim 2 and off): but peculiarly, none of them are selected (see screenshot 1).
Choosing SIM 2 will return the option to Off even though I get a pop-up alert saying SIM 2 will be used for data (screenshot 2) and then selecting SIM 2 for the second time, the setting will take and will activate the data connection (screenshot 3).
I have been using until very recently a Samsung A50, dual sim running Android 9 with the same setup, SIMs, carriers etc and never had an issue. Neither the Calls or SMS settings in the SIM Card Manager get affected.
What I am experiencing feels like a bug in the A51 / Android 10.
I googled around and the people complaining about losing data connections on their phones like I am were doing so back when they had Samsung Galaxy S4 - so quite a while ago.
Anyone have any ideas how to prevent this behavior? Or experienced anything similar?

Related

[Q] anyone getting sim card does not allow connection to this network?

I have gotten this message 3 times in the last 5 days. Each time I need to do a reboot to restore cellular/sms service (toggling airplane, wifi, bluetooth, sync, and 4g do not restore cellular/sms). The phone has the same AT&T sim card since day 1 and I have never removed it.
Is this a faulty phone, sim card or both?
gtabfish said:
I have gotten this message 3 times in the last 5 days. Each time I need to do a reboot to restore cellular/sms service (toggling airplane, wifi, bluetooth, sync, and 4g do not restore cellular/sms). The phone has the same AT&T sim card since day 1 and I have never removed it.
Is this a faulty phone, sim card or both?
Click to expand...
Click to collapse
Did the sim come with the phone? ATRIX 2 needs newest of sim cards to function properly. If that's not the problem then I'm not to sure.
Sent from my MB865 using XDA App
Yes, same sim card that came with phone.
Could be a faulty Sim, i've had that happen before with other phones, just go to at &t and show them the problem, they should replace it for you!
Sent from my MZ617 using Tapatalk
(Hope you understand my english)
I wasn't able to solve this problem about an year. But did. And totally sure that it is Device's defect (in some cases it is a ROM deffect as in my case, in other - hardware. Smth like stack overflow issues at GSM controller or so). A year ago when I had face this "sim card does not allow connection... " problem, there are no google serch results on this keywords request. Any. To remove this message I was ought to reboot my device every time it appears. And I was thinking that it is normal behaviour for my device. But now there are lot of complainings at the web ( minimum 5 of Galaxy Tabs P1000, thousands of HTC Disire, few motorolla Deffy, 10 Galaxy Ace, few of Nexus S and so on), so I understand that I'm not alone, and problem is known. So I went to Samsungs Service and they confirmed that it is famous problem, have flashed my phone with some magic ROM (magic because it is official but does not available anywhere in the web, XDA or samsung sites! ) and now my phone works fine. Any other solutions like battery removing, *#*#4636#*#* sirvice menu, new sim-card, flashing variety of modems and roms, didn't helps me. This is not faulty sim. This is serious device's defect. Bring your phone to manufacturer and let them repair it or give your money back. This is their problem not your.
using old 3g prior sim card
With ATT---If you took your old 3g sim card out of old phone and used it. You will get this message. You need to activate the 4g card that came with phone
537magspc said:
With ATT---If you took your old 3g sim card out of old phone and used it. You will get this message. You need to activate the 4g card that came with phone
Click to expand...
Click to collapse
Not true.I'm using my old 3g sim with zero issues.
Sent from my MB865 using XDA
Same issue in Mumbai India
CS4 said:
(Hope you understand my english)
I wasn't able to solve this problem about an year. But did. And totally sure that it is Device's defect (in some cases it is a ROM deffect as in my case, in other - hardware. Smth like stack overflow issues at GSM controller or so). A year ago when I had face this "sim card does not allow connection... " problem, there are no google serch results on this keywords request. Any. To remove this message I was ought to reboot my device every time it appears. And I was thinking that it is normal behaviour for my device. But now there are lot of complainings at the web ( minimum 5 of Galaxy Tabs P1000, thousands of HTC Disire, few motorolla Deffy, 10 Galaxy Ace, few of Nexus S and so on), so I understand that I'm not alone, and problem is known. So I went to Samsungs Service and they confirmed that it is famous problem, have flashed my phone with some magic ROM (magic because it is official but does not available anywhere in the web, XDA or samsung sites! ) and now my phone works fine. Any other solutions like battery removing, *#*#4636#*#* sirvice menu, new sim-card, flashing variety of modems and roms, didn't helps me. This is not faulty sim. This is serious device's defect. Bring your phone to manufacturer and let them repair it or give your money back. This is their problem not your.
Click to expand...
Click to collapse
I have exactly the same issue randomly at times when I try to register on network manually (MTNL Dolphin 3G - Mumbai). Unrooted MB865 ver 2.3.6 & updated on 18th May 2012 to System Ver 55.28.37.MB865.AsiaRetail.en03. If I keep the setting as Automatic in Type of Network & Operator it functions fine fluctuating between Dolphin for local access & CellOne on roaming access in the same area based on cell tower connection the phone registers on alternating between "E" & "H" automatically based on cell mast direction proximity, however if I select 3G only and uncheck automatic for operator then the phone searches for signal for a very long time and fails to show any operator saying "no connection available" & sometimes when "Dolphin" network does appear and try to select manually get the error as "this sim card does not allow connection to this network". I did complain with the service provider and they were supposed to get back to me after checking in their switchboard exchange where I also provided them my SIM number in addition to my cellphone number(no response). Also as is case with poor service of all Indian cell network providers even in urban cities, also face random peculiar issue of call not being received inspite of signal available on the phone & network asking me to recheck the number I have dialled while placing outgoing calls though it is ok and signal is sufficient. Also "Network Speed Booster" app looks like a lot of bull (any other good apps??)
I needed to know using the secret Menu *#*#4636#*#* for 3G GSM service which kind of network I should ideally select for best results & does this setting override the regular menu network settings??
I get "G", "E", "H" randomly based on my locations but no "3G" or "H+" and further at times these icons are grey and sometimes blue and in either cases randomly at different locations sometimes data throughput is not there as only one of the arrow shows active blinking. Any advise on the status based on colors and the blinking of the arrows?? Thanks!

Dual SIM standby

Hello Team,
I have an issue with my OnePlus 6 about the network connectivity.
If I have a data connection in SIM 2 suddenly if I receive a call in SIM 1. Network connectivity got disconnected. Even though I have enabled the dual 4g settings still the issue continues.
When I have used the Honor view 10 it has the specific setting, like this " Don't disconnect the network data in a call".
Is there any specific setting like this in op6??
Standby phones can only have one connection open at a time. So when the non-data active sim takes a phone call you will lose data. This is true regardless of what networks are connected between the two.
I do know that some phones will automatically switch the data sim to whatever sim the phone call is on. Unfortunately, this isn't the case for the Oneplus 6.

One UI 2 (Android 10 - "BSKO" rom) SIM card manager bug?

Just updated to Android 10 ROM - G970FXXU3BKSO on my international (SM-G970F/DS) Galaxy S10e.
Now, if I set the SIM card to use for "Mobile data" (with one SIM card turned off, and the option of either the active SIM (AT&T) or "off"), when I set the "mobile data" the the SIM card that is turned on, I get a toast mesage that (to the effect of) "AT&T will be used for mobile data", but, when the toast disappears, the Mobile Data setting is either "off" or just not present at all (that is, under "Mobile Data" there is nothing -- blank). If I use the "quick settings", it shows mobile data is on, but it isn't. If I toggle the quick settings to off, then on, it comes back on.
By itself, this isn't such a big deal, but, apparently randomly, mobile data simply gets turned off.
Help???
One UI 2 (Android 10 - "BSKO" rom) SIM card manager bug? - SOLVED
SOLVED: This was a bear to find.
TLDR: This was NOT a bug in the SIM card manager. It was a problem with the Google Fi app.
Google FI app was messing with SIM card control. Delete the app, and all is fine.
Long version:
Android 10 update for Samsung SM-G970F/DS (Dual SIM, Exnos, international version) seemed to break the SIM card manager for the dual SIM configuration.
Randomly, it would set Mobile Data to off, but not gracefully or correctly. Randomly, it would change the mobile data to use the alternate SIM card.
I have a Google FI SIM in slot 1, and an AT&T SIM card in slot 2.
Apparently, the Google FI app *thinks* it knows more than it does about the Samsung dual sim phones, and thinks it wants to switch SIM cards. It would disable mobile data, but not set the "mobile data" flag to "off". So, the mobile data looks like it is on, but, when bringing up the SIM card manager from settings/Connections/SIM card manager, the "Mobile data" was blank (which should never happen), instead of "Off"
Deleting the Google Fi application makes everything fine.
Google Fi app version: December 11, 2019 version. (V22-arm64-v8a-xxhdpi (282453276)

SMS/MMS Compression Issues - Factory Reset and Sim Switching Hasn't worked

This is a weird one, maybe somebody here can help me out. I have a Samsung S10e on Visible (Verizon MVNO) with a really strange and persistent issue. Basically, every MMS received is heavily compressed (<100kb) and only the first frame of any GIF is displayed. I have another phone, a Samsung Galaxy S20 FE, also on Visible, that works without issue.
Here's what I've tried:
1) Factory resetting the S10e and NOT RESTORING DATA
-- No effect
2) Swapping the two sim cards
-- No effect. The S20 FE still gets MMS normally, the S10e does not (RCS disabled in both cases for debug purposes)
3) Swapped an active freedompop (AT&T) sim and factory reset, then swapped in the Visible SIM (there was a similar persistent network issue that was fixed this way on an S9+)
-- No effect.
Now, another wrinkle:: If RCS is used on the S10e, and the other person ALSO has RCS, pictures come through fine (in the same messaging app, Google's official Android SMS app).
Normally at this point I'd request another SIM from Visible, but I don't understand why the sim card would work fine in another phone, and a known working sim card doesn't work in the s10e. It seems like more of a phone problem than a SIM card issue, or some combination thereof. Any suggestions? Many, many thanks in advance.
podspi said:
This is a weird one, maybe somebody here can help me out. I have a Samsung S10e on Visible (Verizon MVNO) with a really strange and persistent issue. Basically, every MMS received is heavily compressed (<100kb) and only the first frame of any GIF is displayed. I have another phone, a Samsung Galaxy S20 FE, also on Visible, that works without issue.
Here's what I've tried:
1) Factory resetting the S10e and NOT RESTORING DATA
-- No effect
2) Swapping the two sim cards
-- No effect. The S20 FE still gets MMS normally, the S10e does not (RCS disabled in both cases for debug purposes)
3) Swapped an active freedompop (AT&T) sim and factory reset, then swapped in the Visible SIM (there was a similar persistent network issue that was fixed this way on an S9+)
-- No effect.
Now, another wrinkle:: If RCS is used on the S10e, and the other person ALSO has RCS, pictures come through fine (in the same messaging app, Google's official Android SMS app).
Normally at this point I'd request another SIM from Visible, but I don't understand why the sim card would work fine in another phone, and a known working sim card doesn't work in the s10e. It seems like more of a phone problem than a SIM card issue, or some combination thereof. Any suggestions? Many, many thanks in advance.
Click to expand...
Click to collapse
Did you ever find an answer to this? I am having the same issue on a new unlocked S10 with total wireless. My s9 received mms just fine, and my s10 compresses every incoking mms and gif to less than 30kb (outgoing works fine). I put my new sim card in my old school and it worked fine, which makes me also think like you did, that it isn't the sim or carrier. Thanks.
Matt
wstcoaster07 said:
... it isn't the sim or carrier ...
Click to expand...
Click to collapse
Could it be Settings? See if you have "Restricted" set, here...
Messages > Settings > More settings > Multimedia messages > Restrictions
This should be set to the "Free" option.
Yeah, it's set to free. I've slso tried other apps like Google messeges, chomp, textra. Chomp no longer has that "legacy" mode setting that I recall was a good fix years ago.

Dual Sim Question

For those on dual sim, does data on the secondary sim ever get used. In Sim Card Mgr there is a toggle to use it during a phone call but other than that , say my primary data sim is poor, I wish it would use the one with the better connection automatically but I do not think this is an option
JeffATL said:
For those on dual sim, does data on the secondary sim ever get used. In Sim Card Mgr there is a toggle to use it during a phone call but other than that , say my primary data sim is poor, I wish it would use the one with the better connection automatically but I do not think this is an option
Click to expand...
Click to collapse
I have a Samsung Galaxy Note, SM-N986B/DS.
No, my experience is, you can't set data usage to automatically,
But why don't you just choose Sim2, for data usage.?
While back i had 2 x Sims in my device.
(One Sim is a just a data Sim, loaded with 10 gigs data each month )
The other Sim only had 1 gig data on it, each month .)
I set my preferences as follow in Sim Manager ......
Calls.... Sim 1
SMS.... Sim1
Data ( mobile)... Sim 2
Worked fine.
No issues.
If i switched my mobile data on it would
use Sim 2 data.
However,
I have since changed my setup.
Took second Sim out of phone,
as i experience
"more battery drain" (overnight )
than when i was using
only one sim and/or sd card.
Good luck.
willcor said:
I have a Samsung Galaxy Note, SM-N986B/DS.
No, my experience is, you can't set data usage to automatically,
But why don't you just choose Sim2, for data usage.?
While back i had 2 x Sims in my device.
(One Sim is a just a data Sim, loaded with 10 gigs data each month )
The other Sim only had 1 gig data on it, each month .)
I set my preferences as follow in Sim Manager ......
Calls.... Sim 1
SMS.... Sim1
Data ( mobile)... Sim 2
Worked fine.
No issues.
If i switched my mobile data on it would
use Sim 2 data.
However,
I have since changed my setup.
Took second Sim out of phone,
as i experience
"more battery drain" (overnight )
than when i was using
only one sim and/or sd card.
Good luck.
Click to expand...
Click to collapse
I have unlimited data with Visible on sim1. I have 2gb of T-Mobile on sim2. If I'm in a spot whereb Visible sucks, I want to switch to sim2
data
JeffATL said:
I have unlimited data with Visible on sim1. I have 2gb of T-Mobile on sim2. If I'm in a spot whereb Visible sucks, I want to switch to sim2
data
Click to expand...
Click to collapse
Yes ,it's was just the opposite situation for me ,where i had more data on Sim 2 .
However,overall i guess it never worried me, as i am 90% on wifi .
I also noticed ,more battery use age of keeping mobile data on ,than wifi.
I guess the only option left ,would be to manually, change to preferred data Sim .
As far as i can remember the best option ,
( when i had 2 Sims in my phone )
i would swipe down to expand phone quick settings
and my Sim preferences , showed ,just under the phone ,quick settings icons .
I would then long press on the preferred data Sim choice and change it there.
It was better than going all the way to Sim Manager .
Good luck
willcor said:
Yes ,it's was just the opposite situation for me ,where i had more data on Sim 2 .
However,overall i guess it never worried me, as i am 90% on wifi .
I also noticed ,more battery use age of keeping mobile data on ,than wifi.
I guess the only option left ,would be to manually, change to preferred data Sim .
As far as i can remember the best option ,
( when i had 2 Sims in my phone )
i would swipe down to expand phone quick settings
and my Sim preferences , showed ,just under the phone ,quick settings icons .
I would then long press on the preferred data Sim choice and change it there.
It was better than going all the way to Sim Manager .
Good luck
Click to expand...
Click to collapse
Hmmm, the battery thing is interesting. I've tried so hard to get dual sim, flashing TMB onto Unlocked but now the battery thing is a bummer. If that is what causing it. I just turned off 120 refresh rate to see if that improves battery
In Quick Settings I see where I can click on one of the sims on the top and it takes me to the sim card menu but I wish it were just a toggle instead of taking to the menu
JeffATL said:
? Hmmm, the battery thing is interesting. I've tried so hard to get dual sim, flashing TMB onto Unlocked but now the battery thing is a bummer. If that is what causing it. I just turned off 120 refresh rate to see if that improves battery
In Quick Settings I see where I can click on one of the sims on the top and it takes me to the sim card menu but I wish it were just a toggle instead of taking to the menu
Click to expand...
Click to collapse
Firstly,
Yes, only thing you can do
is "toggle" it manually, like you described.
Secondly,
with 2 x Sims in my phone
i found that my average "sleep" over night
was example......
+- 12 % battery drainage, over period of +-8/10 hours (sleep.)
Further the way i see it,
is that even with phone in
sleep mode, it still trying to get better signal reception.... x 2...? whilst
This i checked via Betterbattery app.
Secondly,
I am back on one sim.
My average sleep overnight is
8 % for 10/12 hours sleep.!
Bottom line,
It's your phone.
That battery diffs, is no big deal...
For me it was an irritating issue. thats all
If you happy with 2x sims
keep it that way!
Good luck
JeffATL said:
For those on dual sim, does data on the secondary sim ever get used. In Sim Card Mgr there is a toggle to use it during a phone call but other than that , say my primary data sim is poor, I wish it would use the one with the better connection automatically but I do not think this is an option
Click to expand...
Click to collapse
Previously, say I had Sim 1 for data and Sim 2 for calls and i got a call on Sim 2, then Sim 1 was unable to access data but this has now changed with N20U
If I understood this correctly then I think my device is different cos regardless of which Sim is primary or secondary, I have an option under settings>connections>mobile networks> allow all Sims to use data in calls, which I can toggle on or off. I have found selecting this allows the other sim to use data which was not possible in some earlier android versions.
william-johnson said:
Previously, say I had Sim 1 for data and Sim 2 for calls and i got a call on Sim 2, then Sim 1 was unable to access data but this has now changed with N20U
If I understood this correctly then I think my device is different cos regardless of which Sim is primary or secondary, I have an option under settings>connections>mobile networks> allow all Sims to use data in calls, which I can toggle on or off. I have found selecting this allows the other sim to use data which was not possible in some earlier android versions.
Click to expand...
Click to collapse
But not when I'm in a call. I needed to use data from my secondary sim because I was in a dead spot for first sim. I had to go to sim card menu in settings and change primary sim and then change it back eventually. I did use the shortcut from the pull down menu but I wish I had a toggle , ideally from Nova Launcher
I am interested to purchase a SM-N986B DS for my dual sim work/personal cell in the US near NYC. I have metro PCS and Verizon. Will this phone allow verizon to operate as the second sim? It would be a non-data sim. I know it is a GSM phone and not CDMA but also read that the LTE bands may be compatible at 4g/5g. Curious before I take the dip to buy and find out it won't work...

Categories

Resources