This happens whenever I'm on cs skill with charges on.
I tried to click on the mobs and click again to move around quickly (run) . The charges drops and there's an action of attack but no arrows/skills came out and no damage either. Basically the char stops to show the attack action but nth happens and the skill charges dropped by 1. Happens on multi fire and shark missiles. Not sure about ex can't try it yet.
Doesn't happen with normal attack. Tried with normal attack and it works where i click on the mob and run the arrow still shoots and hit the mob with damage.