Full screen bug

I'm really not sure why it happened but it was very strange. I loaded into a game of ARAM and all I could do was target ping, move, and chat. I couldn't do anything else. Strange lines kept appearing on the top of the screen.

Around the 10 min mark my screen moved a bit and everything was fine.

I was using btw (yes haha hes a bug)

This is the game I was in http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2027668804/205555311

Unfortunately I could not record this bug because I could not exit the game when it was active.

Any questions I'll happily answer.