CI Build Instantly Dying Without ES Loss — Possibly Chaos Damage Bypassing ES?

Hi everyone,

I'm currently playing a Chaos Inoculation (CI) build and I've run into a very frustrating and confusing issue. I have around 7,100 Energy Shield and CI is definitely active (1 life shown, CI node taken).

However, I constantly getting one-shot in some situations without losing any Energy Shield at all. In the latest case. I died instantly, and my Energy Shield bar didn’t even move.
Here’s what I’ve confirmed: CI is active (1 life, flasks of life disabled, character sheet shows Chaos Immunity).

My build: https://poe2.ninja/pob/6753

Any help would be greatly appreciated — I love this game but I’m at a loss with this issue.

Thanks!

Heavy Buffer passive
40% increased maximum Energy Shield
5% of Damage taken bypasses Energy Shield

Thank you very much, I was starting to go crazy.