Sometime after the launch of Dragonflight, it seems a bug was introduced where certain class characters with the required revive class ability are unable to resurrect Leroy Jenkins.
Quest prerequisites:
-Dungeon type set to heroic.
-Dungeon is located within BlackRock at Burning Steppes (not the Draenor version)
-Character has a garrison (WoD expansion) and can collect followers
-Character must have class-specific resurrect ability (does not include Hunter, DemonHunter, Rogue, Mage, or Warrior since they do not have this ability)
Classes which have been confirmed to work: Monk, Druid, Priest, Paladin, Shaman
Classes which have been confirmed do not work: Deathknight, Warlock, Evoker
Issue:
After eliminating first 2 bosses, Leeroy Jenkins is found incapacitated and must be revived. You may not use an item such as brazier of awakening or ultimate gnomish army knife, and must revive him through a class ability.
Expected Result:
Resurrect revives Leeroy, who then prepares some chicken and then loots a mob to obtain an item called “devout shoulders.” The character with the res ability simply clicks on Leeroy to revive him.
Actual Result:
Hovering your mouse over Leeroy highlights as a usable action. Clicking on Leeroy Jenkins animates your character with what would be a resurrect motion, however does not revive Leeroy. Also, using your class ability (clicking on the resurrect from your bar) does not work.
I have taken the time to compile a video showing it failing or successfully working for different classes. The video is posted to YouTube, here:
There is also an earlier walkthrough YouTube from a few years ago showing the steps to obtain the achievement, a number of new comments from users reporting the revive not working have been posted, here: