[BUG] Draven axes being cancelled

So, I have no idea if this is an intended bug, but it makes no sense. If the time spent for the attack animation has finished and the axe flew away which means the projectile is on his way, why do I often have axes ending up being cancelled. Watch the following video:

https://youtu.be/WvQNKlNhdkY 00:33, When garen comes top towards me, after I hit E i go back for one more hit to reset my axes, it just gets cancelled.

https://youtu.be/ClgQKYSL6Cw 00:17, when I try to las t hit that creep, auto attack gets cancelled again

Happens quite often and it is very annoying when I miss the last hit on champions on creeps. I can't find any explanation for this since the axe leaves from draven which means the AA has been "initiated" but the axe deals no damage and doesn't return.

Any info ?