Barrage - seemingly off cooldown but does not activate

Sometimes the Barrage skill looks to be ready to use but nothing happens when you click or hold the button for it. Waiting some more time holding/clicking the button again makes if finally activate. Frustrating when collected frenzy charges and trying to activate it within the timefgrame of charges.

+1

I just had this happen multiple times against Zalmarath. I stood in place mashing the skill looking for ANYTHING to happen. When it activated, all 25s of Frenzy charges had ran out haha