[HELP] Can't identify symbol

Hey guys. I have been having some issues with World of Warcraft in the last few days, and with Legion launching in just a few hours, I'm at my wits end.

I am having issues with keystrokes sending properly to the game, and it only happens in World of Warcraft. I have to press the same button multiple times to get it to work once. Nothing has fixed this, not even reinstalling the game. The only thing that has worked temporarily is doing a repair of the game install, but the next time I close the game and reopen it, I have the same issue.

Coincidentally, World of Warcraft is the only application where I see this symbol, down in the bottom right corner. http://imgur.com/13QZN1Y

Has anyone seen this before? What is this? Thanks in advance.