Hi Wolfgang, as promised I'll give you a feedback on your suggestion.

Unfortunately my trial failed.
I set Simulator for the Mount, Focuser and Guide (just to be conservative) and I check the Train set for the captures in Light Mode (I attach some images).
After these checks nothing changed with respect to my previous attempts.
I attach the last Log file. It seems there's something that occurs working only in light mode (no problems with Dark, Bias or Flat modes).
I hope we can find a solution for this.
I am available for further attemps in the settings.

Thank you again.

Frank