On Emby Theater (latest) in Windows 10 (1803) the mouse cursor reappears when media change happens, and does not disappear after.
Click on episode 1
Move cursor to lower corner of screen out of habit
Media bar and cursor eventually fade out
Finish episode 1
Mouse cursor reappears in lower corner and never disappears.
This gives me the angular resize cursor in the lower corner when I'm binge watching and it drives me bonkers.