Bug in The Cloaked Ascendency Campaign - Nostura Quest Line

The quest line for Nostura is broken. You get a quest line for Khabal, Gyrion, and Nostura from the same NPC. There are pre-req quests to progress, then the last two quests in this line are to investigate their pasts and defeat them. I've started all 3, investigating their pasts, then going to their plane with each character's stone. However, even though I have both investigated Nostura's past in the campaign AND the next campaign section to confront Nostura, I still cannot progress further because the quest line is still showing that I need to "investigate Nostura's past" in the campaign. I initiated the next in her campaign tree hoping to trigger it and complete the investigation quest, but had no luck. This has resulted in about two week's worth of lost scrolls since each task takes 120 scrolls. I've abandoned the quest multiple times, but each time I pick it back up, it still shows where I left off, as not having Nostura's past investigated. I know this is an older campaign and no one needs the gear anymore, I'm just doing it for the boons and the shroud.