Thanks for the review and a bug report! Regarding this issue I was aware that going into theater or fullscreen modes and back breaks it but it's weird that it can happen without any user action. I'll try to fix the bug that occurs when changing modes today, however the scenario where is occurs by itself will require more investigation.

EDIT: Try now.
EDIT2: Saw your edit of the edit quite late but I've noticed it breaks when zooming or resizing the page. I'll try to fix it soon.