Anyone did "Free Knot!" quest in Dire Maul North recently?

I saw multiple people are looking to get "the insane" achievement as well since they are purchasing libram and/or heavy junkbox on global channel. I wonder if anyone had done Free Knot quest recently where you need to go to Dire Maul north to rescue him with Goblin Shackle Key.

I run and reseted this dungeon but Knot Thimblejack didn't even spawn.

I was wondering if there is any certain "requirement" that I must do to make him spawn? or this is simply a bug?

Please advise fellow achievement hunter.

Greetings,

I assure you Knot Thimblejack spawns. I checked by entering Dire Maul North directly, as well as accessing him from Dire Maul East (tunnel at the end leads to DM North).
I took this screenshot today on Icecrown, within the past couple hours. As far as I'm concerned, there is no special requirement to having him spawn. I did however clear the bosses on the way, but I don't think that's so important.

https://imgur.com/flWfIpy

Make sure you're in DM north, I've been lost there plenty myself. I recommend the Atlas addon, likely the best marked maps for dungeons for finding Bosees/Quest NPCs in dungeons.