Champion select, open Masteries, press 3 times space bar - cant select champion

Just started Ranked game, guy told in chat to open masteries and press 3 times space bar. After you do that you can't select any more masteries nor exit masteries window which results in not being able to pick champion, now I probably lost some LP and got 5 min ranked game ban. Can you fix that bug Riot? Tested again vs bots and took screenshot. I just saw some posts here regarding that thing someone posted like 2 months ago and looks like you didnt fix it. This is ultimate troll thing and you should fix that asap, it is UNBELIEVABLE that game has that bug. You NEED to give that bug maximum priority.

Best regards, Isus.