Azir, Disc of the Sun

So i've been playing Azir for a long time and i've noticed there's something wrong with Azir's passive. I dont know if its a bug or not. But i've been dived multiple times for a long time, and my turret just sits there farming minions instead of attacking the enemy champion. It doesn't seem like the turret has penetrating bullets either, everyone just walks past the turret like it's nothing.