OK Firstly the latest version of Plex for Apple TV is just awful. I have gone from not having a single issue to a literally unusable release. The app freezes, becomes unresponsive, videos won't play. Anyway onto the main issue, videos simply won't play. I hit the play button, screen goes black for a second or 2 or even doesn't do anything, it will sometimes ask if I want to resume or start from scratch and then does nothing. I think I have narrowed this down to only MKV's, I have converted the same files to Mp4 and they play fine. BUT ALL other Plex clients as well as Infuse for Apple TV will play these mkv's files fine! This is on 2 TV's and 2 Apple TV 4's both are the same.
I'm using latest version of Plex, latest version of Plex server for Synology and later version of TVOS for ATV.
Any help would be appreciated. Thanks.