Stuttering audio output

Hi - first post

I have a Raspberry Pi4B - Allo Digione Signature - Moode - LMS

Built this system a week ago and it has worked flawlessly and sounds brilliant - as good if not better than my Ultrarendu

A problem has started today - after a few minutes , audio starts stuttering , gets worse then stops altogether. Tries PiCorePlayer instead of Moode - exactly the same. Guys on the Moode site thinks it is LMS config issue

Any Expert opinions ??