Something in Simul is depleting my HP and bypasses ES

Here's a clip for reference : https://www.twitch.tv/velyna/clip/HilariousCrunchyTortoisePraiseIt-dXoG4pyjD_U8q4Tu

Same kind of thing is damaging me and bypassing my ES in Simulacrum.

It's not drowning.

I don't THINK it's chaos, because my chaos charm doesn't proc when it happens, but that mob she was highlighting had "extra chaos damage" as a modifier. Could it be that if that mob uses a different element as damage but has that modifier, that it bypasses energy shield?

Someone help me out here.

Thanks