To be specific: In full screen mode it turns off the screen after a while and so far I could not find any setting that disables this behavior. The things I found on the internet where about dimming the screen and the suggested solutions against it did not work for me. It seems that is goes into "audiobook" / "listening" mode for some reason.
When I press the power button of my smartphone again the video player is a floating mini player.
When I press the power button of my smartphone again the video player is a floating mini player.