I've had a somewhat similar event happen twice today...
Using JRemote on an iPad to initiate playback of a full album (just over 60 minutes, for the second case) via Kodi running on a single-board computer (ODroid), playback has just stopped. Hitting play again on JRemote gets things going again. For the second case (which just happened) playback stopped 5 seconds into track 13. The album has 18 tracks total, with about 19 minutes remaining in the album.
Earlier today, with someone working on the computer, playback was fine for what seemed like hours. (To be honest, though, since no problems was cropping up in that period of time, I'm not sure exactly how long it was.)
My thought was to wonder whether anything changed in MC with respect to managing sleep?
(MC 26.0.18 on Windows 7, JRemote 3.30 on iOS 13.3, DLNA playback to Kodi renderer)