S21 update to Android 12 - SIM continuously resetting

[gpaolo79]

Hello,

three days ago I have received the update to Android 12 on my Galaxy S21 5G   and, since then, the phone is almost unusable to make phone calls

Both sims reset themselves periodically, within minutes, dropping the network and any phone call in progress. 

After trying to reset the network settings, the phone has started to request the pin for the sims at each reset, so I had to disable it. Keeping one or the other sim active only isn't changing the behaviour. 

The diagnostic on the phone doesn't detect any issue even if run while the network is down. 

Does anyone incurred in the same issue or found any solution? The phone is 3 months old...

[gpaolo79]

I had a chat yesterday with customer service, but still no solution.

They made me do a setting reset, but it still doesn't work.

I'm trying their suggestion to check safe mode, but I have already seen a reset. I'll check for a few more minutes just to be sure that it wasn't just a glitch.

Next step... factory reset. I hope it would be worth the hassle, at least... I wish it were possible to talk with some real expert on this, obviously the general customer support only follow the restart-small reset-complete reset steps blindly...

[gpaolo79]

Great, factory reset done for nothing. SIMs are still resetting. Saying that I'm upset it's an understatement.

[gpaolo79]

So, I have spoken again with customer service, their only option was to ship it for repair or book a in-home repair. Both are not viable for me, shipping takes too long and the earliest in-home appointment was after I will leave, so nothing to do with that one either.

I have spoken with technical service in Italy where I bought the phone, and where I will be for the next weeks, and after telling them what happened they said that at 90% it's a bug in Android 12, like the one with whatsapp, and hopefully Samsung will come out with a patch, but there isn't anything that they can do if even the factory reset didn't work. They said that they will raise the issue officially with Samsung Italy and that they will let me know.

[gpaolo79]

I have spoken today with two repair centers in my area.

They are both aware of this issue and they have a number of phones having it, also of different variants of S21 (so it's not limited to a specific model).

One center was willing to replace the motherboard, but there are none in stock, even in the central Samsung warehouse. The other one insisted to wait, saying that there is no guarantee that the issue will not happen again with a new motherboard, as they are 100% sure that it's a software bug not related to the hardware. It's not really consistent with what I see here, but, anyway...

One interesting bit of information: I mentioned the possibility to revert back to android 11. One said that it can't be done officially as the downgrading is not supported and they can't get the image from Samsung (fair enough). The other one said that it won't matter because the update also changes some firmware on the motherboard. It's the first time I hear it, but if it's true, that would explain why reverting to android 11 would not fix the issue once it's present, as at least another person was saying in the forum.

So they both told me to wait for an official update. I'll speak with them again next week, one of them seemed really keen to push with Samsung on this issue as they had a number of phones in this situation.

[hasham11]

I am having the same issue and every time the network goes, the flight mode icon greys out, as if someone had just switched flight mode on and off. This is definitely a software glitch and Samsung needs to fix this ASAP! 

[Erik Friis-Dahl]

Same issue here.  I also ordered a new sim card which I just activated an inserted, but I still have the same issue.  Network keeps switching on/off and the flight mode icon greys out.  I can see that several users have done a factory reset without any luck, so I do not want to do that.  I really hope that there will be a new software update ASAP

[gpaolo79]

I'll call them again on Monday.

One things that I have noticed. When the glitch happens, I see that the notification and time displayed on the screen with the smart cover closed get also reset one moment, and when the phone is on, everything gets refreshed.

I wonder if what is happening is something more "deep" in Android and the reset of the SIMs is just a side effect of a more general reset that happens, like if some internal task crashes and it's restarted.

Has anyone else noticed these other signs? 

[gpaolo79]

I have called, they keep getting the answer from Samsung to wait for a software update and do nothing.

[gpaolo79]

reading on other forums, it looks like Samsung has removed Android 12 and the BUL6 from the servers, around today or late yesterday. Maybe they realised the size of the screwup made with this update and something is moving...

[gpaolo79]

Samsung officially cancelled the rollout of Android 12 on S21 family:

https://www.sammobile.com/news/samsung-halts-galaxy-s21-one-ui-4-0-update-google-play/

https://tecnoblog.net/noticias/2021/12/21/exclusivo-samsung-interrompe-android-12-para-galaxy-s21-no...