I need remote access to diagnose, can't find any obvious issues.

Jasem, feel free to contact my if you wish

If you have StellarMate, open a ticket and then remote support would be easy.

If he doesn't I do. I can upgrade that one computer again and set the rig up and see if it does it again since I do have a fall back system that I can use if these clouds ever leave.

I don't have stellarmate but kstars on a minipc. As my colleague Tracy, I'm running a "main" system and a backup, so I can run both versions. Feel free to connect remotely if needed

I will update my 1.8.2 install on that NUC and see if it is still doing it. If so, I'll enter a ticket over at StellarMate to get Jasem access to take a look at it.

Just did an upgrade and it made me reconfigure my device connections (the serial related ones).
Once I did that it seems that it's not doing any non-requested moving now. Will play with it and see if it does it after I make some adjustments to the angle via the camera rotation control.
This upgrade also seems to have reset all my settings that were present for the camera settings (gain/offset) the filter that was default and several other things this time that it did not do last time.
The rotator is also moving VERY slowly when moving to the new position on 1.8.2... taking so far about 20 minutes to move even a few degrees. The rotator is only moving the 100'th degree at a time rotation whereas on 1.8.1 it's moving in whole degrees and doing so rapidly.
Ticket being submitted to Jasem at this time.
Ticket ID 400

Believe this is fixed now. Jasem may chime in and detail what the issue was, but he was able to access my system.

could you please explain, in the meanwhile, if there is any workaround?

It was a driver issue. Jasem apparently fixed it and stated that an update would be pushed out to the INDI PPA sometimes within the next 24 hours.

great. Thanks a lot guys for your effort

Can confirm that my Pegasus Falcon is working fine on StellarMate 1.8.2 now. AFAIK the update has not been pushed out into the stream yet as when I just did (yes, I know playing with fire) an SM Update to pull in any new changes nothing was there.
But I'm happily capturing M81/M82 and the camera did have to rotate to a new angle since it had been moved around and I was doing a load & slew from earlier captures.