Nice job with that test! Is this the Alnitak CoverCalibrator driver? It should release everything when the AutoFlat script ends. No need for that Dispose(). I don't explicitly call Connected = false; though. So far no one else has reported any problems like this since 9.0 came out in March 2022. That was the first version that supported CoverCalibrator devices.

This one is going to need to go to Optec. Are you sure you have their current driver?