Sion ult blocked by friendly Azir wall.

I'm sorry if this bug has already been reported but a friend and I noticed this bug a little while ago when playing a twisted treeline. I was playing Sion and used my ult and as I was charging down my friend playing Azir ulted to try and keep them near me but the all got away and i hit the wall stopping me from chasing them. Afterwards we did several customs trying it with and without items. It didn't matter whether it was the front or back or side of the wall, he would always stop and do the knock up. This may not be a big bug but the tool tip on Azir's ult says it allows allied champions to move through it freely. Thanks for reading, Mazuri.