[GAMEPLAY] Mastery Bug

I just finished playing a game as Janna with my support masteries. Next game I'm playing Brand mid, select my AP mid masteries but when I get into game, I had my support masteries. I join next game and when I look at my masteries, it is showing my AP masteries but for some reason, I went into my last game with support masteries. I think it also happened a few games ago prior when I was Janna but had AP masteries. Not sure how to reproduce, just started getting this issue last few games.