I use my car's Bluetooth to answer phone calls. While I was all happy with this option, I had to update my Moto G6 from Oreo (v8) to Pie (v9). Soon after the update, I had to root the phone for the call recorder to work.
After all these steps I got complaints from my callers that my voice is very feeble. I had to yell to repsond back. I was not sure whether it is the mic in the car dash is an issue or my phone or my carrier. I tried the same setup in different places to isoloate the carrier issue. I gave my phone to my wife and used her phone to connect to car and made a call from her phone to mine. She was able to hear my voice clearly from natural speaking and seating position. This ruled out the issue with my car leaving the issue on my mobile.
The same hardware was working fine before the update so I guess this should be a software issue. I tried to tweak the Bluetooth settings under developer settings and found no luck. Sure I can factory reset and even rollback to Oreo to isolate, but that is too much of work for me.
Are there any means for me to adjust any settings to increase my mic's volume (sensitivity) for Bluetooth communication? The callers are not complaining when I use the phone normally or via speakerphone or via headset. They complain only when I use the car's Bluetooth facility.