Sejuani Q Bug

If an enemy champion is standing against the wall that Sej is trying to Q over, then Sej will initially pass through the wall, knock up the enemy champion, then get pushed back across the wall to her original starting place. I find that it happens most often at the ledges behind the wraith camp in between the pathway and the river, probably because it's smaller than most walls, but if positioned just right it can happen on most wall jumps. Not only does it look extremely glitchy, but there's nothing more frustrating than jumping on the enemy jungler for a surprise counter gank only to find out that I can't follow up with any of my damage and leave my team hanging while I'm stuck trying to figure out how to get over the wall now.