Unable to complete Expedition Quest/Akt 4 Expedition / Plunderer’s Point

Hello Support Team,

I’m currently stuck in Act 4 at the Expedition quest in Plunderer’s Point. I joined a party instance of a friend who had already completed this part of the content.

After that, the quest appears to be bugged in my own progression. Dannig/Denig no longer spawns in any Expedition encounters, and I am unable to interact with him anywhere. The Expedition quest cannot be continued or reset from my side.

I have already tried:

Creating new instances of the area (Ctrl + Click)
Logging out and back in
Waiting for instance resets
Re-entering the zone solo

Unfortunately, the issue persists and I seem to be soft-locked from progressing the Expedition questline.

Could you please assist with resetting my quest state or restoring NPC/quest progression?