[Bug] Act 4 Progression Softlock – "The Search" stuck on "Speak to the Hooded One"

Bug Description:

I am completely softlocked at the end of Act 4. My main story quest "The Search" is stuck on the objective "Speak to the Hooded One" in Kingsmarch.

However, unlike the common confusion where players just need to explore more areas, I have already fully cleared 100% of the archipelago maps and defeated every single island boss, including the final encounters. My map shows all island nodes completed and connected, and I have no other campaign zones left to explore.

When I return to Kingsmarch and click on The Hooded One, the dialogue window opens completely blank with no text options, showing only the "Goodbye" button. I have tried changing my Hideout layout with Ange, creating new instances of Kingsmarch (via Ctrl+Click), and restarting the game, but the NPC remains completely bugged and refuses to trigger the final dialogue to progress into the endgame/mapping phase.
Steps to Reproduce:

Complete every single island encounter and boss objective in Act 4.

Return to Kingsmarch with the quest tracker showing "Speak to the Hooded One".

Interact with The Hooded One.

The dialogue box opens completely empty (except for "Goodbye"), blocking all further character progression.