When I first flew my LIV, I was having complaints about my transmissions.  Very noisy.  Turns out it had not yet installed the inflatable door seal, and the wind noise was jamming the microphone.  The guy in the right seat did not have the same problems.  We thought it was problems in the wiring.  But once the door seal was installed and inflated and all leaks checked, the complaints about my transmissions stopped.  The transmitter is a Garmin 430. Headsets were Lightspeed XM25’s.

Your problems may be more complex, but the audio noise in the cockpit without a door seal is something to consider.

Fred Moreno