Yeah, you mentioned sometimes the pattern won't clear, I've had that issue too. I
've had to manually put notes in using the knobs, fixing the velocity which is in no way reminiscent of how I played the notes, fixing the gate which just does what it feels like
then the whole machine glitches and the whole thing started playing three octaves down with gates at 1. Just for fun.
I've been sick so haven't had a chance to hook up to other instruments yet. But midi to volca shouldn't be this problematic.