FH-P8000BT Double Din CD Receiver

Hello, I am new to this forum. We just purchased and installed this unit into my 2000 Ford Excursion. Everything went well in the install and everything tested ok. I have the BT microphone connected and mounted in the center of the dash. I paired my phone and that went fine. But when I got an incoming call my caller could not hear me and no callers since then can hear me. What do I need to do?