When using the sleep timer while playing audio tracks, the timer will disable itself when there is a track change and keep playing until manually turned off. The sleep timer functions correctly if the track is long enough, i.e. the track is an hour long and the timer is set to 30 minutes. The timer also works correctly if you choose the “play until end of track” option. My server is running version 1.20.0.3125.
I don’t know if this behavior is older, but I only started using the sleep timer when I updated to 8.4.0 (arm7) and it’s always been a problem.
If this is a server or app setting please let me know.