The window of the player is shifted - in classical mode with decorations. Also the main manu can´t be used, as it can´t be seen. Experienced with the player launched, when installed both from package and from sources too.
The "temporary" solution: Press F11 - go to the fullscreen - then the main manu is visible.
Could it be the problem, that should be solved only by the developer of the app? Than maybe the packager could know, how to explain it to him.
Assigning to the registered maintainer.
Sayonara 1.0.0 available. Last update on December, 31 2017
Is this solved in latest upstream release?
Can you test the Cauldron package?