I was having this problem a lot as well but think I have it figured out. I don’t believe it is a Mac or a drone problem. Remember: the video is recorded on the S2, the audio is recorded on the phone. Once the S2 has landed, your phone THEN starts uploading the audio file to the S2. This takes a little time, longer for the longer flights. If you power-down your Skydio2 too soon after the flight there will not be enough time & kinda screws up the transfer & maybe even damages the audio file? To be sure all is good, directly after the flight try viewing at least just the beginning of the file in the Media Browser in the app- it won’t start playback until the audio is transferred & sync’d. Otherwise, you can actually find the copies of the audio files on the phone by connecting your phone to iTunes, selecting your phone & going to the “File Sharing” tab, and then select the Skydio 2 App. Select the “com.skydio” folder & then click “save.” Your audio files are in there.... as well as the flight logs & everything else. You can then use QuickTime to add the audio to the video manually. (Sounds way more complicated than it is.)