[GAMEPLAY] anoying bug/glitch where i cant move my champion.

I was playing a ranked flex game as katarina, when suddenly i couldnt move my champion... And no, it was not lag, I had 86 ping I could write in chat normally and see others play but i couldnt move... After a short period of time it was ok and i could move but it kept happening sometimes into the game. This sh!t happened 3 games in a row and it is pretty anoying to deal with. If you could fix it or tell me whats wrong i would appreciate it.