Chayula Monk with Darkness vs Ground Fire

I've been trying out the Acolyte of Chayula with the Darkness branch of the ascendancy.

I've noticed that the Darkness buffer is instantly removed by ground based fire effects, for example the fire circle mod that some rares have.

My suspicion is that Darkness does not benefit from my resistances in this instance (possibly all instances).

Not fixed =(( Same with any dot damage (poison, bleed, ignite).
Why so not popular class have issue with properly working tallents (