CLIENT: Masteries changed in new champ select do NOT apply to your game if saved <5 sec before game

When changing a mastery page in the new champ select, it says the confirmed changed message that is something like: your mastery changes have been saved. However, I would get into game and realize that i still had the masteries from before i made the changes. very frustrating when im in a rush to puck my masteries, i change all of them, click save glad that i finished in time, then its a huge buzz kill when i get into game with a windspeakers blessing on garen, or a bond of stone on ap brand. Please resolve? or at LEAST make it so that it notifies you that it was too late and your masteries never saved. idk, when it gives you the reassurance that it saved your changes, then you get into game, it really messes up gameplay. or a grasp of the undying on a sona. so much health stolen...haha Thanks riot for fixing!