[Client] Mastery points on some Champions are NOT rewarded after game

Hello, I have expirienced this many times. After a game (ranked or normal) i am NOT rewarded the mastery points for my champion. There is a circle of blue light that goes in circles like its loading , in the place where should have been the mastery award circle for my champ. I dont mind this happening once, but iv expirienced it a lot, and became irritating :( Anyone knows how to fix it? Thenk you.