Mana stacking gear question

Hi there fellas, my first post on forum ever, so if I confused the section or made mistakes in the post structure: sorry in advance.

So I have Eldritch battery allocated together with The Everlasting Gaze unique amulet, so that all of my ES is converted into mana and a portion of my mana is gained as baseline ES. Assuming that I understand how it works, the more mana I have the more ES I should be getting. But for some reason it does not work exactly like that.

For some reason a rare focus gives me more ES but less mana, and a well-rolled Machination, which gives me a lot of mana, seems to decrease my maximum ES. I dont' seem to understand why is that

Items and screenshots of stats below (if I did set it up correctly)