Star Guardian Lux's Ult did not Register. [Bug]

There is something going on with Star Guardian Lux's Ult, the enemy takes no damage when her ult animation appears no one in the ult get health depletion. i saw it point on that lux ulted an enemy ziggs when he was 5% Health and he didnt die. I also saw another time in the same game our enemy lux with star guardian skin hit us with her ult when we were all in dragon pit no one in our team got damage. Im pretty sure the ult hit us.