i had an A4/OT combo issue recently that was borne of having them bi-directionally wired in Turbo mode - even though the OT was not receiving transport, it was transmitting the note information from the A4 mini keys equating to transport commands back to the A4, so the A4 sequence got restarted when i hit the b key, the OT sequence was not affected (due to settings), but it still resent the rcvd command out the OUT port strangely ! i haven’t heard back from hq yet - but check the midi plumbing too

there was a previous forum issue with regards to a spurious cc command affecting the fine control of an a4 param, this was down to a parameter spuriously reacting to a cc message which was one part of a valid nrpn pair, it meant that the affected param could be partly and incorrectly targeted, but i thought this got fixed - anyway, the point was to look at the back of teh pdf to see which midi commands are connected with the fine part of osc1 and try to work out if they could be coming from anywhere in your setup,… of course, it also might be a gremlin, but as mentioned above, best to be methodical