Bleeding concoction and Energy shield mobs

I am playing with Bleeding concoction and have problem with mobs that have Energy shield, especially I met rare one that I actually could not kill because concoction does almost 0 damage to ES and my flasks just go to zero before even removing ES. Should not bleed from Bleeding concoction bypass ES?

From what I gathered so far, Monsters and Players can only be bleeding with hits on their life pool. As long as they have Energy shield up, they are practically immune to bleeding. That's why CI characters are bleed immune aswell. I don't know why GGG decided to make the mechanic this way in PoE2, but it certainly bricks bleed builds.