Reporting a bug for Tahm kench

I'm not sure if its just me but every time I try to use W (devour) It doesn't always work on allied champions or even enemy ones (yes with max stacks on) I would spam "W" over and over and it doesn't always work when you want it to. However it seems to work on minions just fine for some reason.

And yes my keyboard is perfectly fine, I never had this problem with any other champion before.