Brief description of the issue:
The LIPB airport from the official marketplace seems to be corrupted. If I compare pictures with the sim lots of things are missing or even aircraft are standing on top of the building, some mentioned airplanes are not visible at all. Signs, monitors and people should be there but are missing too.
All in all this thing seems to be corrupted.
I’m not using dev mode and removed all other external plugins/mods.
Hello! Did you forget to turn off Bolzano from Asobo in the settings ?
Ok, found some time to investigate. First I saw the BMW addon only in the marketplace content manager when searching for LIPB. And that’s what I saw
In DevMode I found the scenery package order tool with some rankings and corrected them for bmw scenery (3) and microsoft scenery of the airport (2). With some success.
Then I realized that I could click/open the World Update with the list icon on top and single-selected the Microsoft LIPB airport - and deleted it.
The result looks way better
I don’t know whether that’s the correct way to solve this but it seems to be working 
So thanks for the advice @BMW969
