QML app crashes on full screen manipulation

Hello there,

In my windows application I am changing the ApplicationWindow and its sub Window's visibility during run time between Window.FullScreen and Window.AutomaticVisibility. During the application run, I encounter a crash described in this post:

https://forum.qt.io/topic/104291/qplatformwindow-requestupdate-assert

As suggested in the post, I have changed the MinGW x64 compiler to MSVC 2017 x64 which I thought solved my problem. But I then started developing the code further (without touching this functionality even) and the problem returned:

The application is quite big now and I am not able to provide the whole source code. But I am really willing to help solving this bug. Please let me know what else would be needed from me to help here.