Call issue (mute) after Android 16/One UI 8 update

[djgusmy85]

Hi everybody,

A few days ago, I updated my S25 to Android 16/One UI 8.
After that, the calls have occasionally gone mute. I speak, but the person on the other side can't hear anything. The microphone works properly because with other apps (e.g. voice recorder), it can be heard normally.
Restarting the phone the calls works for a while, but then the problem recurs.

Has anyone else had the same problem?
How can I fix it?

Thanks in advance.

[Members_BkoW0kb]

I have the same issue here. S25 Base model 256GB, unlocked (no carrier). Started to happen after the ONE UI 8 update. The phone has been purchased from Samsung Online Store directly, and it is currently still under warranty 
Apparently, cleaning the cache partition doesn't help
I can also confirm that other VoIP apps (Telegram, WhatsApp) calls work as expected, tested with the very same caller on the other side.
I also tried to disable the WiFi calling feature, but it doesn't seem to be the cause. 

[roerisi]

I found the solution. Given the persistence of the anomaly, we recommend disabling the 2G network while waiting for a definitive resolution by Samsung technicians, which will occur through the release of a new firmware