DUAL SIM issue since One UI 4 update

[Drazuhl]

Hello,

I've  had a big issue since the update with my network.

Any time I'm outside (with no Wifi) even if there's good 4G coverage, I randomly (and sometimes constantly) lose network on both my SIMs (both from the same provider).

I'll try to use internet, then I'll get the "forbidden" logo on both SIMs for a few seconds instead of the network bars (the Airplane mode symbol will also look like it's activated for a short while), then the SIM will show the normal bars for a while, sometimes Internet works then, other times it just repeat the same cycle.

I've ended up completely unable to use internet at times.

Here is a Video of the problem 

I've tried many things, changing different settings in the SIM section, resetting the network settings, forcing reboot (volume + ON/off button),...

I've realized that when I deactivate one SIM (either one), I do not have the issue with the other SIM, so this seems to be related to dual SIM, but they were working just fine before the update...

Can anyone think of a reason why this is happening? I really do not want to factory reset / send back my phone...

Thank you

[xSteveuk]

Hi,
There are a few issues
With the android 12 update
Hopefully these will be fixed on the next update

If you haven't cleared the phones system cache

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

[gpaolo79]

There are a number of discussion about this, for example my thread here

https://eu.community.samsung.com/t5/galaxy-s21-series/s21-update-to-android-12-sim-continuously-rese...

Factory reset didn't solve the problem for me. I'll try to bring it to tech service tomorrow, but what I hear here is that even reverting to android 11 isn't working. People are talking of the need to change the hardware...

[gpaolo79]

by the way, with me (also dual SIM), disabling one or the other didn't change the issue, I was still getting it.

[Drazuhl]

I guess it's "good" to see that I'm not the only one having the issue, I hadn't found any on google or here with the search engine.

I'm not 100% sure that using only 1 SIM only is entirely removing the problem, it might have just happened less frequently.

Please keep me posted if there's any development on your side, for now I'm mostly in a wifi environment but it's quite problematic as soon as I get out of home...

[gpaolo79]

This is another one:

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

Thank you for posting the video, that's exactly what happens to me as well.

The funny thing is that, with me, it seems that it is happening always at the same time, at minute 4 and 9 (04, 09, 14, 29...).

[gpaolo79]

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@Drazuhl wrote:

I guess it's "good" to see that I'm not the only one having the issue, I hadn't found any on google or here with the search engine.

I'm not 100% sure that using only 1 SIM only is entirely removing the problem, it might have just happened less frequently.

Please keep me posted if there's any development on your side, for now I'm mostly in a wifi environment but it's quite problematic as soon as I get out of home...

---

Before doing the factory reset, I was getting it every 20 minutes or so, and going to one SIM only was indeed making it less frequent, but still there. After the factory reset I'm getting it every 5 minutes...

The worse part is not much about the data stopping for a moment, it's that phone calls also drop! The phone is basically useless at the moment, I can't make calls. 

[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! 

[normalee3]

Guys, you have to go to: Settings, then Connections then SIM card manager then choose which one to disable. It supposed to work. Yes you have to do this every single time. As for me I do this whenever the other sim ran out of load balance.
Been experiencing this problem since the last major software update around 3mos ago if i remember it right. Then almost weekly update from there on. 

[ROnm1]

I am also having issues since the last one Ui 4 [android 12] update. I have dual sims connected on my galaxy s10e but since the update the sim on position 2 is not working properly I can phone out but cannot recieve calls. If I switch sims around the one on position 1 works fine but not the one on two. Nothing wrong with the sim itself as works fine on a spare phone. Phoned my carrier and he mentioned there was probably a software issue which seems to be the case given the research I've done. Hopefully samsung will give this some urgency and fix this soon with another update. Funny though, my wife also has two sims in her s10+ and has had no issues!