Playback hangs after a while

I’ve been running LibreElec Kodi on my Pi 3b+ for a while, which plays my library of mp3s fine but hasn’t the nicest of interfaces. So I downloaded Volumio a week or so ago, and that was fine - until I played an hour-long file of around 20 mp3s and it hung up after about 45 minutes. I tried a different equally long file with the same result. No matter whether I played the files off a plugged-in USB stick, read them from an NAS or received them from a Twonkey server, the result was the same. Playback would suddenly stop and start and I would be unable to connect to Volumio either by browser or ssh. Reverting to Kodi, the same files played without hiccup. Kodi’s ok, but particularly as I forked out a few quid to upgrade Volumio I’d like to get it working ptoperly if I can. Any suggestions?