When I enter the fullscreen mode of youtube under firefox or chrome, the youtube player is aligned wrong. It shows a white bar at the top and hides the control buttons of the player while only showing the edge of the player progress bar. This happens directly after going to fullscreen and there is no change when i move my mouse. It just stays the same state.
I tried cleaning the cache in chrome first, but i think it's a problem with youtube because i have exactly the same phenomenon under firefox. Other video players (e.g. vimeo, dailymotion, reddit video) work without problems in both browsers. How can I change it to normal again?
Ubuntu 18.04.2 LTS
Chrome Version 74.0.3729.157