Champion Select Bug

So i was in champ select, and i went to change my mastery. Seems normal right? But when i hit space bar a few times while in the screen to change the mastery i got this white blank screen in the shape of the mastery tree. I couldn't pick a champion resulting in a wait timer for the next que, and -3 lp. Not much but still would like to know how i can fix that while in the champ select screen or if that is a bug that could be fix.