Cho'Gath Feast (R) cooldown bug.

Happens at least one time per 2ish games as Cho'Gath. You cast feast on a target below the execute threshold. This can be a minion, monster, or champion. The spell seems to go through but you do not get the kill and an ally does (ally getting the kill seems to be important, as iirc it does not go on cooldown if the target is killed by a minion or enemy champion).

Your ultimate has dealt no damage and goes on cooldown. When you ping your now-wasted ultimate, it displays as being available. When an ally pings it this is also the case. I assume this isn't intended. My recommended fix would be out the ult in cooldown after the damage goes through rather than at whichever point the cooldown currently begins.

Have a nice day