Azir/Illaoi Interaction Issue

So I just played a game where Illaoi could jump using Harsh Lesson through Azir's Emperor's Divide. He specifically cast it while she was jumping to push her away and the wall did not knock her backwards like it should have. Anyone else had this issue happen? It was very frustrating because Azir was using it to push enemies off of me, Jinx , and Illaoi kept getting through somehow. If the ult had gotten off properly, those team fights would have been much different.