[CLIENT]
There is a bug with the new champ select where your masteries do not get saved if you change them and rename during champ select. If someone q dodges after you change it, the name will be right but the mastery page will be the old one. so far i have tried this 2 times and it has worked both times.
i have only entered a game once while doing this bug, and the mastery page in game was the old one, not the one i made in champ select. cannot say the replication rate for this part of the bug.