[GAMEPLAY] Illaoi's E doesn't go anywhere and hits nothing

Sometimes when I use Illaoi's E, the ability doesn't go anywhere and will act as if it hit a wall, when there's no wall around.

1. Walk on top of a minion, or stand on a newly placed ward that's still visible.
2. Cast your E in a direction where it would hit the minion or ward, but is not directly casted towards it.

I believe this is the best way to recreate it, though it doesn't happen every time, so I'm not sure if that's what causes it.

This happens almost every game that I play as her, and in some cases has lost the game for my team because it then goes on cooldown and we lose the fight because the spirit didn't get pulled (the should-be vessel lives in a 4 for 5 with low hp, wins game). I rarely have it happen on top of minions because I don't usually fight on them, but it happens every time a ward is placed on top of me as I cast my E.