Amumu Ult bug + Smite bug

Noticed a bug in the last few games I've played, Ult going onto cool down but not physically happening in game, same as smite. Example: went into a 2v1 and pressed r, no visual animation or stun on targets as my ult usually would, but i had a cool down after, and same fight i smited dragon to secure, and same bug happened, went onto cool down but nothing visually happened. So that was nice/