I've bumped into this strange issue while working on fullscreen functionality in embeddable element. Entering entering fullscreen on element that is inside an iframe and exiting it by pressing ESC key on the keyboard breaks the whole fullscreen functionality on the entire page! webkitRequestFullscreen simply stops to work on any other elements. 

It can be seen here: https://wojciechczechowski.pl/webkit-fs-bug/

This is really problematic, as it may cause break of the users website functionality as soon as he uses fullscreen on my custom, embedded element. Therefore I kindly ask to address this issue ASAP.