Playing these files on the web player is fine, the audio get’s transcoded. Playing on Samsung Smart TV also works through Direct Play. But on Android every file with E-AC3 audio doesn’t play, I instead get the generic error message “An error occured while attempting to play this video. Please try restarting both the Plex Media Server and this app.” Peeking in the logs reveals that the server decides audio transcoding is necessary, but the transcoding job is never started.
Edit: I forced a transcode on Android by connecting remotely through my mobile data. After that, connecting and playing through my home network miraculously works again.
Server Version#: 1.19.1.2645
Player Version#: 7.31.0.16802