[Client] Masteries window won't close in pregame lobby.

I don't know much about this, nor have I ever posted here. I just just in a ranked queue, last pick, filling AD, so i started making my masteries. As i'm looking at the other team comp deciding what AD to go (before i touch any masteries), my page flashes - the masteries that were green flashed orange or red or whatever color they are when they're maxed, then back to green. I thought that was a bit strange , it has never happened before so whatever, Then i go to close out the masteries window and select a champion and it did "closed" but a "background" of the window was still open. I could type in chat, and i did get responses from the other players. I could barely get my cursor into the champion search bar. However i could click nothing underneath this background the masteries window left. i was spamming for any champion just to not lose my elo. I was kicked from the game, got a 5 min timer and still can't tell if i lost my elo. :c help me rito.