[CLIENT] Masteries window can't be closed

During ranked i had to redo some masteries. When i was done i think i hit the save button at the same time as it was my turn to pick or i tried to close the window at the same time as it shifted to my turn. I was not able to close the bugged window, but still able to write in chat. This resulted in me not being able to pick a champion and got banned from ranked for some time.

It is the first time i have experienced this.