Tahm W Bug ( Not getting to taste my allies)

I know its just the second day out of Testing and all, but i believe that i found a bug in his Devour Ability. Im having a Problem where He wont EAT an ally, and ive had trouble and game criticism based on the fact that i was trying to save a teamate, and tahm just WOULDNT eat him/her. its not always, its centered MOSTLY during teamfights, or when the target is moving. I told a teamate to stop moving and let me eat him to test this and even when i basically was stepping on him, tahm just would not eat him. and i dont believe it was because of his champion size (it was a TF)

On another Note, He Sometimes wont eat an Enemy if the have 5% life or less as well. ive had 4 deaths that devour would have saved me, but wouldnt cast.

Another thing i saw, but i dont know if its just me or a bug itself, when i cast Devour on a minion, Sometimes it goes straight to cooldown without letting me control when to spit the minion out.

I seriusly hope that you guys look into this because i am Loving his playstyle and i wish to make him one of my mains, just for the fact that his kit is VERY unorthodox. Thank you for this champ. Now fix those problems plz :).