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...

[garethcia]

The "door step" repairs are carried out by a company called WeFix..... they come put and work on your phone in the back of their van. Took just over an hour. Keeps guarantee up by using Samsung repairers so no real issues is there? 

[JLerrdh]

I have this exact issue and put in a message to Samsung support on the members app. I received a message a few days ago that it was escalated but nothing further. 

I'm going to hunt through these 9 pages to see if there's a way of accelerating Samsung's response. This phone is unusable on mobile data at present when it's doing the sim cycling. 

[gpaolo79]

No way to accelerate the response, I'm afraid. In my case I could do the home repair because I had to leave and there were no available dates. I'll be away again soon, hopefully in March I will be able to reopen my support request and ask for a repair. At the moment, I went back to android 11 (although its not possible any more if you have updated to version BULF).

[JLerrdh]

I am indeed on BULF. Argh! Id happily accept home repair, in store repair or other.

I'm lost on whether this is a hardware or software issue from the thread though, you're suggesting A11 fixes but a repair would mean A12 works.

Grr. 

[gpaolo79]

It's hard to say.
It's something relatively rare, apparently present also on Pixel 6 phones, definitely linked to android 12. But it can't be a pure software bug, because otherwise everyone would have it. Those who get the phone fixed get at least a new motherboard, which is hardly a small change - it's basically a new phone.
Up to a few days ago I would have considered it only an android 12 problem, but once I noticed it also on my phone now with android 11. It could have been a glitch, it could be that on android 11 happens once every week or month, or enough rarely for not noticing it.
I don't really know... I can't try newer versions or I won't be able to go back, and the phone becomes unusable. I'm hoping for the next update that should come out in February with UI 4.1, otherwise I'll go for the repair.

[HaCet]

Same problem here, S21 Ultra. Is it possible that the new motherboards have another modem than the Samsung 5123b? Because the problems look related to android 12 causing the 5123b modem to bug. I hope there will be an update soon, otherwise will send it for a repair / replacement.

[gpaolo79]

That's a very good point. It would be nice to get some answer from Samsung...

[gpaolo79]

It looks like there is another patch out today. I see that from BULF we have gone to BVA9, at least for my phone with ITV country code. Has anyone tried that?

[JLerrdh]

Not seeing that update yet here. Still BULF for me.

[gpaolo79]

Yes, oddly it seems to have been released for ITV before everyone else...