Possible Katarina Bug?
Okay so this has only happened a few times (cause it's hard to do) but when using E with katarina to avoid certain CC abilities like Ahri charm for example, sometimes it will still hit her even if visually it missed and you will be CCed when you land.
It kind of feels like how Yasuo's Windwall used to not block projectiles on cast so he would still be hit until it popped up and i think katarina could use a change similar to that so that when you avoid someones skillshot it doesn't feel like you were cheated.