Azir soldier's auto attack do not proc Braum stun

I recently played Braum support with an Azir mid on my team. Azir roamed bot to gank, so I engaged and proc'd my stun stacks on one of the enemy bot laners. Azir threw down a soldier and starting auto attacking the same enemy, but the soldier's auto attacks did not add stacks to get the stun off. I think the soldier's autos should proc the stun stacks since they are an extension of Azir's auto attacks.