Likely has something to do with its zoneOrSort tag in the database being -121.

https://classic.wowhead.com/quest=5103/hot-fiery-death

Version 6.0.2

We don't have a Blacksmithing or Profession category yet. There's a feature request for it here: #2073

That's not the issue, the issue is that it's not even showing up in the "Unobtainable Quests" lists with the other profession quests.

"Zone" is "Blacksmithing". That quest is done in "Winterspring" but it's not in the "Winterspring" category by Blizzard.
All these are missing at the moment: https://classic.wowhead.com/profession-quests#0+12
All "zones" under 0 (-121 in this case) are categories (events, war effort, blacksmithing etc) so the data is correct.

In that case all the other profession quests are in the wrong "zone", as they do show up in their respective geographic zones' Unobtainable Quests lists.

@Cerby3BR Yeah some has been "corrected" as I remember correctly to show up there, but a lot are still missing. I hope to really have some time soon ™️ to add a hidden, class and profession list to the Journey.

Feature request for more categories can be found in this issue: #2043

Will be fixed with #2043 - closing as dupe.