Phone powers off when Mic becomes in use

Hello,

I have a OnePlus 6 device and whenever the Mic becomes in use, the phone will power off.

If I try on a call, recorder, text to speech, ok google etc… Anything that causes the Microphone to come into use will cause the phone to shut down.

I have tried resetting the phone to factory settings, and also replaced the daughter board that carries the microphone but still no joy.

I have tried searching online, forums etc and cannot find anyone with the same issue.

OnePlus 6 - A6003

Android Version 10

OxygenOS Version 10.3.7

Can anyone shed any light or ideas on what I could try to resolve this issue please?

Thank you :)