Can we fix the tryn ult bug already :-/

too many times i hit the ult and the game just decides the ult was never actually clicked... please code it like zhonyas to immediatly cancel any incoming damage... its a lil rediculous to have a champ go "immortal" for 6 seconds only to have the green circle dissapear as if you clicked the ult but it not actually being turned on.. at 30 MS this should never be a thing