Devourer on Aatrox

I got a issue with Devourer item on Aatrox. I saw that the sated Devourer item does not activates the Aatrox's W passive properly. The life steal on Aatrox's W does not activates well on sated devourer. As well as the attacking move. As Jax, the passive attack should be work every second attack, but only Aatrox doesn't works well. Jax has no problem. Please know this.