Bug - Azir abilities interactions with Yasuo passive

I noticed some bugs: 1.Created a custom game. 2.I picked Yasuo , There was an Azir in the enemy team. 3.Azir Q hit me, Yasuo shield did not proc even tho the flow was full, but the soldier attack did proc the shield. 4.Azir's Disc of the Sun fired at me, Yasuo shield did proc unlike when he is hit by normal tower which would not proc his shield. I was wondering if this bug is intended, but Yasuo shield won't proc? That's just unacceptable :)