Compiling the project in debug mode just works fine.
But for the store submission a release mode compiled version is required.
Therefore, I started to build my app in release mode and had to determine that the whole app is unusable, because of performance issues. After some try and errors I encountered that only if I enable "Build with .net Native tool chain" that problem occurs. I checked some forum posts here, and one said that maybe the wrong "Microsoft.Xaml.Behavior.Uwp" is installed. But that was not the case.
Thanks for any help in advance