expedition mobs

I've got my build to a decent place and i've messed up expedition enounters before so I try to be careful but I litteraly can't damage these mobs not even the greys. Could someone point out what I messed up?

I assume monster elemental resistance is caped at 75% and chance to avoid all damage would also be simlarly caped but I don't know for certain.

I pulled some of the weaker mobs to a far corner of the map and tried treating them like a boss fight and did not see any movement of their health bar.

https://imgur.com/KM1cUVr

I had an expedition Mob not register my attacks about a week or so ago. Not sure what caused it but 100% has happened to me.

Maybe read what the remnants say before blowing them up? Especially the ones with yellow text.

If you look at the imgur link it shows exactly what remnants I exploded. None of them were yellow. Maybe I did read them and am asking what ones I should have avoided as it's not clear.

I mean its pretty clear to avoid the ones that say "IMMUNE to damage of "X" type" if you deal that type of damage. There's also the buffed ones forgot what they were called, but they have Life Regen so if your damage isn't high enough they will just regen through it.

one of the items says "monsters have 120% chance to avoid all damage from hits", so i guess that explains it.