I don’t use this option very much but with V1 DVR it worked.I tried listening to playback audio and dead silence so I tried the following.
 
 If I plug in AV out to my TV and vtx is transmitting from camera and microphone is used I can hear and see what camera sees and microphone hears from quad or what goggle screen produces. If I use ear phones I can hear what the microphone picks up when vtx is transmitting to receiver.
 
   But if I playback recorded DVR footage from goggles and leave cord plugged in as it was in scenario described above the TV screen turns blue and no video or sound.I see video in goggles but it’s not playing back on TV screen.Also no audio if I try to listen to DVR playback.
  
  If I remove SDcard and play on computer it works properly with sound.

 I didn’t have this problem with V1 DVR playback.What ever was recorded on DVR played on goggles screen or whatever A/V output was plugged into plus sound.

 Is there a different format I need to use or maybe the DVR doesn’t have playback ability through the AV output?
 
 

  
 It’s not feature that is really needed but since it worked with V1 it’s kind of got me curious.