[Zuldazar][War Campaign] Mission Report: The Great Seal

[Kate6]

WoW Freakz link: https://www.wow-freakz.com/quest_helper.php?quest=54225
Character name: Frenzetta
Bug description: I had the mission fail on this character several weeks ago, have been checking regularly and it hasn't come up again. The item that starts the quest chain for this (https://www.wow-freakz.com/item_finder.php?item=165728) cannot be purchased again. Surely there's supposed to be some way to get a second try at this mission?
Proof:

[Curoro]

Character name: Quollucifer
I have the same issue as you.
I've tried the mission using the item https://www.wow-freakz.com/item_finder.php?item=165728 . Unlike the other 2 Outpost Upgrade (Nazmir and Voldun), this mission failed: it does not appear anymore in the list (as it should, to give me a second try), nor I can buy it again from the emissary vendor.
Adding screenshots as proofs.

Proof:
https://ibb.co/m6mvSPy
https://ibb.co/34ZJy2S