[GAMEPLAY] Kayn's Q cancellation

There are numerous things that I've encountered to cause this bug, but they all produce the same result. You press Reaping Slash (Q) as Kayn, and nothing happens but the ability goes on cooldown. Here are a few times I remember this occurring, they have all occurred when stepping out of a wall when in Shadow Step (E) and trying to attack something. There is no 100% way to replicate the problem, and it seems to happen randomly.

1: Shadow Step into attacking Gangplank, who then ults just as I use Q in his direction. Cancelled my Q. 2: Coming out of wall and attacking Gromp occasionally will cancel the ability. Maybe Kayn gets stuck between the wall and Gromp? 3: Similarly to #1, ganking anyone with soft CC (slows), using Q just as they use their slow will sometimes cancel Kayn's Q. This only happens occasionally, as stated before.