Aztiris Disdain Gold Circlet Bug

I have eldrich battery and mind over matter passives activated in my skill tree so all of my ES is converted into mana. I am trying to use Aztiris disdain to gain a further 30% of my maximum HP into ES and then convert that into mana but it’s not working. I’m only getting mana from the stat bonuses on the helmet not the 30% ES I should get. Is this an intended feature or a bug?