thermalmonitord error with mic1 - rebooting every 180 secs

Hi, my phone suddenly started to automatically reboot every 180 seconds. The error log is mentioning an error with the thermalmonitord on the sensor mic1.

I've sent the phone to the maintenance as it is still under guarantee and they stated that its the screen that needs to be repaired and that this is not under maintenance.

The screen has a little crack on the top right but that was there since a year and I really don't think that was the cause.

Can you tell me if anyone experienced such a problem and how you solved it?

Thanks

Ame