Cleanse bug patch 5.15

In one of my ranked games i picked Oriana as midlaner, they picked ww jungler so i took cleanse for stoping his ult... the game has begun and at the first gank at lvl 6, i died cause of his ult, which weren t stoped by my cleanse.. such a bug and , i heard that Twisted Fate's stun has the same bug , i m waiting for your answers, if its just a bug, or if they can t be stopped .