Android Question New project -> dark theme is set automatically -> XUI view not working properly

Today I started a new project, in the manifest the theme was automatically set to


I first added a RoundSlider which wasn't shown correctly (the value in the center wasn't visible). In all examples the light theme is used.


Maybe I missed it (and how XuI views work) but the view should check and handle this. Another thing is that it must be square. Why? Here the view should check the biggest "square" (more exact: circle) possible inside the given height/width including the thumb.

Am I wrong here/missing the basics?