Just checking in again to see if anyone at Plex has anything to say about this issue.
Note that with just a little bit of looking you’ll find many threads on this topic, such as this one:
I have tried the preview version of PMP 3.0 with the updated MPV player and see no change. Still get random audio drop-outs. It does seem that this problem only affects some users, passthrough must be working for some people. This would cause me to initially question something about my hardware or drivers, but I can confirm without question that playing the exact same movie file in VLC or in Kodi works with no issue using passthrough, so this brings us back to a software issue in Plex.
Any progress or comments?
