[GAMEPLAY] Buff Mobs animations bugged?

I played as Rengar a week ago and used the blue buff bush to jump to blue buff, when I did I landed in an awkward space between the buff and the back wall. The buff immediately froze. It sat in one spot and would not move and I was not taking damage. I thought this was as isolated incident until I played Yi yesterday and Qed in the middle of a buff attack animation, the buff immediately froze again and would not attack me. This free happened 3 times that game and 2 more the game after.