Hi @stevieq, sorry to hear about this.
The main microphone of the XA2 is located at the bottom of the frame next to the USB-port (see point 12 in this overview), have you been able to check so that this microphone is not blocked by any protective cover, dirt or lint from a pocket? Also, have you been able to carry out a quick test of the microphones to see if they work as intended? Find and tap Settings > Support > Xperia Tests > Speakers & microphones.
Another thing that you can try is to reboot your phone in safe mode to see if the microphone works better there. Safe mode is a troubleshooting mode where all apps downloaded from Play Store is temporarily deactivated and by doing this, you can see whether this behaviour is caused by a downloaded app or not. For more information on safe mode and how to use it, click here.
If the behaviour of the microphone persists in safe mode, I would suggest that you try to repair the software using a computer and Xperia Companion. Keep in mind though that a software repair will erase all user data from the phone, so make sure to do a backup of your user data before the repair.
Try these measures and let me know how it goes!
