essentia sanguis doesn't work

the leech doesn't recover the energy shield even in the passive tree and gear i have life regeneration per hit and damage

im testing it to useing Whirling Assault Skill
And Even the Tool Tip in game when you equip the item "essentia sanguis" you see the tool tip change In game live from "life leech" to "Energy Shield Leech"

but attacking a Mob no such luck :)

when and If it get fixed man o man it going to open up some crazy cool build ideers :)