Mastery screen glitches in champ select [CLIENT]

I redid my masteries, saved them, closed the screen and it didn't close. It just left this on my screen so I couldn't change my summoners and had to dodge rather than jungle without smite. Clicking the 'x' multiple times on the mastery screen wouldn't close it.

No idea how to reproduce or how often it occurs because I've only gotten it once so far.