I just read-skimmed Sub-snapshots not saving information reliably .
One suggestion, which I do understand if you feel it’s too much effort - see if you can reproduce under Vangelis, preferably with a fresh sd card. I will try to reproduce under Oram, but it might be a while, my Zynthians are on various levels of Vangelis.
Also can you reproduce without the external MIDI controllers-input devices? They seemed to be the source of the problem a while back, and I realize we might have to deal with it, I’m just trying to troubleshoot and wondering if they have been taken out of the picture.