FPSController + WebGL = Issue (Case 839177)

Hello everyone!

When using the FPSController in a WebGL build, the controller will lose control when the mouse gets out of the player area.
Like that, the game can't be played.

Has anybody else had this issue and maybe knows of a workaround?

You can check a build including this issue on my website here:
http://shushustorm.com/ShushustormHeadquarters.html

Best wishes,
Shu

EDIT:
Alright, if at some point the player is not online anymore, I decided to abandon browser integration. I am currently thinking about it, because there seem to be too many issues going on. FPSController doesn't work properly (with Firefox, the whole thing sometimes even crashes), communication to .html doesn't work as intended
( https://forum.unity3d.com/threads/cannot-call-javascript-on-html.435270/ )
and in Safari, the WebGL player's appearance outside the game window isn't proper either.