Zed's Q not being thrown or goes through a champion without applying damage [GamePlay]

I tend to play zed a lot, and though this bug only happens once every 100 q's or so, it is still annoying. Zed's q from time to time does not get thrown and more annoyingly it does get thrown but does not get thrown from his shadow. I have lost only 3 or 4 kills because of this, but it is still annoying.