Tahm Kench W not working on allies and enemies

[GAMEPLAY] Tahm Kench - Devour not working on allies and enemies, but works on minions

Couldn't use Tahm's Devour on allies or enemies with 3 stacks, I'm pretty sure I tried to Q - W combo a minion and it died as I tried to devour it. Couldn't Devour allies and enemies after this I'm pretty sure, and I lost a game because of a few deaths in the early game where I couldn't save my allies or devour enemies. The ability was highlighted until i died and I had to exit and reopen the game to fix this because I was unable to use it all game.