Sion's Q

Sion is one of the main champions I play and lately I have been noticing a bug with his Q when you use it on minions. When I clear minion waves with Sion I fully charge his Q the use my E (clears all but canon). That works 95% of the time, but sometimes when I use my E after the Q the minion doesn't move like it should, it still kills minions touching the minion that I use my E on and the minion I used the E on, but it won't reach the back of the wave.

Yesterday when I got into a duel with the opposing top-laner, Nasus. I charged my Q to hit him, I hit some minions too, then continued to chase the Nasus. I noticed that one or two of the minions I had hit where just floating in the air. Until that point I wasn't sure if the bug was coming from the Q or the E, but it is now clear that the Q is the buggy ability. I only noticed the floating minions once. As far as I can tell the bug is only on minions, if it is happening to opposing champions I haven't noticed because Sion's E doesn't knock back champions. This bug makes it harder to farm and poke the opposing champion. I frequently launch a minion to poke or even kill other champions, it hasn’t happened to me yet but this bug may prevent a Sion player from getting kills.