[Gameplay] Ally Azir's R (Emperor's Divide) blocks Sion's ultimate

Recently I played ARAM as a Sion and I had Azir in my team. I noticed that the wall Azir created with his ult actually stopped my ulti, while it shouldn't, because, as a description says:

> When the soldiers finish their charge, they stand as a wall, blocking enemy champion movement and dashes. Allies and Azir can pass through the wall and gain 20% bonus movement speed when they do.

So basically, Sion's ult should easily go through ally Azir's ult, but it doesn't.