Unable to complete quest that affect progress

Support Bug Report
1

I have a quest that keeps showing up on the map: “By the Sea, Nevermore”. And it aborted my quest line, which shows on the right side of the map: Pandaren Campaign Quests: 8/10. It makes me feel so bad.
When I query the task code and execute the result，
/run print(C_QuestLog.IsQuestFlaggedCompleted(31089))
Return false
/run print(C_QuestLog.IsQuestFlaggedCompleted(31682))
Return true

2

Sorry, this is a problem encountered by my level 70 hunter

3

I can’t get this quest 31089, I can’t see the NPC.