Software updates on IPhone 8.

When Apple did software updates for IOS 14, I think it was 14.2 or 14.3, I lost audio on FaceTime calls. I can hear them they can’t hear me. I have audio with Siri, Voice Command, Zoom, YouTube etc. I also can’t set up my voice mail with a greeting. I had read others had this similar problem and that it should correct itself on the next updates. Did not happen. I had to change my carrier to Mint. I can read a voicemail but no audio. Any suggestions or research available. Thanks so much. I can’t afford a new phone at this present time.