FP4 Microphone not working on loud speaker on GSM calls

I was not talking about cleaning anything. I was talking about testing the mics.

Edit:

To nit pick: you had an issue that was fixed and was not about bad GSM=2G calls

and now you have an issue with Android 13 which is still not about bad GSM calling.

and this issue here is a third one reported under Android 12

And for def of GSM, this was discussed here.

Overall lot of reports and a bit difficult to follow what the current problem is.