Tristana ult not knocking back target

You can see in the video that the Camile has already used her e and ult before I used tristana's ult. You can see the ult going off with the cooldown being on 90 second cooldown in video but the Camile doesn't move at all. There is no other displacements that could cancel the ult affect either. You can clearly see the Camile has no items that could cancel the knockback.