Cursed Spirit Can't be killed for Achievement Tiny Terrors in Tanaan

[Beastsam]

Following previews post: Please try to understand the problem before closing the post ignoring the problem.
All the guides for this battle are for battle of 3 vs 3 and not 3 vs 1 extremely over powered pet. The battles on youtube are pretty easy:
https://www.google.com/search?q=wow+cursed+spirit+battle&&oq=wow+cursed+spirit+battle&&aqs=chrome..69i57j69i61j0j69i64.10384j0j7&sourceid=chrome&ie=UTF-8


WoW Freakz link: https://www.wow-freakz.com/quest_helper.php?quest=39162&&&&name=fel-legendary-pet-tracking-quest-4

Bug description: Cursed Spirit have high speed so It goes first doing skill 2 (Ghostly Bite) doing at list 866 damage + Stun, then Skill 1 ( Fel Corruption)
hitting around 600 damage all the pets. My pets have so low HP left that is impossible to even hit the Cursed spirit below 50% wile he heal it self. After cooldown again,
skill 2, then 1 and all pets are dead.
I tried to kill it at list 25 times. I used Mechanical pets, Undead, Critter, Elemental, Flying (to try to hit first), Nothing works.

Most pets we fight against have different order of moves and when they are hard to kill, we depend on luck that they won't use skill 1 at the beginning or even at all in
the fight. The problem with Cursed Spirit is that it always use it and repeatedly.


Proof: https://imgur.com/a/ltPwP9k
https://imgur.com/a/1xDJhhH

Please fix it. Lower the speed, lower the crazy damage, make it to not use skill 1 all the time, just please do something so it will be kilable.
Thanks.