Evading/teleporting mob in last boss in Necrotic Wake

Everytime, on my hunter character, as soon as i get dark exile, and hit the mob, its starting evading and teleports up. It happends in necrotic wake. It just cost us a 15 run. We couldnt finish it, untill i just simply dropped dead, and they 4 man it. I dont use any skills, just aa it, and it runs to the wall, starts evading and then just goes up, killing me and rest of the group. I have no pets, since i play mm. it cost my lost time of me and my friends. its infuriating.

i have found a video with exactly the type of an issue i have

not my video, but exact issue i was having