Hello Umberto Thanks for investigation
Sending you a screenshot with the cubes, and ball and jetways.
On the same screenshot I have added the content of the GSX customize airport LSZG with parking 1/JS
and a part of Virtuali-GSX-lszg-mjvx4q.ini
I tried to deinstall LSZG and I also change the jetways in the lszg-mjvx4q.ini to 0 but no success.
Hope for further help
regards Roger