Warwick's W is Glitched

(I tried to record it but black screen was popping up in video)

His W (blood Hunt) has a glitch where it doesn't go off at all. even though there are enemies alive it just doesn't work, you don't get any of the active effects of it either it just doesn't function at all. It'll work time to time but once it hits late game it seems to stop working. I've played 5 games with him and 3/5 had this issue.