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...

[xSteveuk]

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]

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]

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]

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]

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]

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]

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

[gpaolo79]

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

[Rūmøur]

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-...