I’ve had similar issues. I’m not sure it’s always the cause but when i’ve had issues they seem to crop up when i get playful w/ the cue points. Most of my play once I get a loop going seems fine and i’ve left the unit running for hours w/o issue, it’s jumping around or adjusting the loop points where I occasionally run into snags.
It’s only been once (and I think I did a very fast power cycle) that I found a reboot didn’t fix this, but w/ that said I recall at least once where a power-cycle didn’t fix the lock, but a second longer power cycle did fix the problem.