Azir Ultimate Bug
I'm not sure exactly how to recreate this but it happens to me on an extremely frequent basis as Azir -
When Xin Zhao jumps to me with his E and starts attacking, my ult does not shove him back and away. It just passes right through him. It may do damage, but I haven't been able to notice since I'm usually more concerned about the fact that he's still sitting on top of me.