Solved: S21 update to Android 12 - SIM continuously resetting

gpaolo79 · ‎02-12-2021

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 · ‎30-12-2021

So, after that one Samsung center refused to change the motherboard, another tried but Samsung cancelled the order of spares and now I don't have time to wait any more, I decided to downgrade back to A11 and it seems to be once again stable.

From the next version the bootloader should be different and not allow the downgrade to A11 any more, so if you have these problems, I would suggest to downgrade now, don't enter wifi during setup, go straight to software update and disable them before doing anything else.

For me, A12 can wait. I am not impressed with Samsung, one month of time wasted with a non-usable phone, and at the end I had to "solve" it by myself reverting back to the previous version of Android. Not good at all for a phone of this price.

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xSteveuk · ‎02-12-2021

Hi,
Try clearing the cache

https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/

If that doesn't resolve the issue
Perhaps a phone reset
((Back up phone)) If do a reset

gpaolo79 · ‎02-12-2021

Hi, thanks for the suggestion, unfortunately clearing the cache didn't work. After 10 minutes, both sims reset again.

I would keep the phone reset as last resort. All banking and security applications take a very long time to restore, it took me days to get the phone up and running when I bought it... so let's see if there is any other idea before trying that...

gpaolo79 · ‎02-12-2021

Does anyone know how to report this to Samsung and request support? I have left the feedback yesterday from the mobile phone but I have got no reply.

Cactusking · ‎03-12-2021

I've been having the same issues with my S21 Ultra. My phone will just stop recognising my sim card and just show me a circle with a line across it, cutting me off from my calls and the Internet. I've done cache clearing, factory resetting, and even got a brand new sim card. I can only boil it down to the phone having the issue. I've booked a repair with Samsung and hope they can fix this. Otherwise the phone is literally unusable.

gpaolo79 · ‎03-12-2021

I'm trying a suggestion i have found online. I'm not sure yet if it's working, but the phone does seem more stable.
Someone with the same problem, although on a different phone and on an older version of android, had the same issue and solved it by swapping the sims. I have done it, and I have received the configuration messages for one of the Sim. I haven't seen resets yet, but I'll see today what happens.

gpaolo79 · ‎03-12-2021

Unfortunately I have to report no success. The phone seemed to be more stable, but I just had a reset of both sims at the same time.
I'll keep searching...

gpaolo79 · ‎03-12-2021

There is an update available, I have just installed it. Let's see if they have fixed it.

gpaolo79 · ‎03-12-2021

Nope, just had a reset. The update didn't fix it.

Rūmøur · ‎03-12-2021

As you can see, you arent the first to face this issue. People have been facing this for months with no solution still.

https://eu.community.samsung.com/t5/galaxy-s21-series/s21-ultra-no-network-conection-after-the-last-...

S21 update to Android 12 - SIM continuously resetting

1 Solution