Warwick's W not activating when requested [GAMEPLAY]

For about the past 2 months now I've noticed that on occasion Warwick's Hunter's Call, his W to increase attack speed, doesn't proc when I hit the hotkey or select the button in game. This happens in spurts; it will not work for a few minutes then magically start working again. I've noticed this for awhile now.

I mostly notice it when I'm in the middle of a huge fight and constantly try to spam W in hopes that it procs, which it doesn't. Then after I die and revive, it works again, only to become stuck and unable to use at another point in the game. It occurs at random, and it's frustrating