Shang's third request bugged?

[wraith4001]

I wasn't aware Shang gave out other maps to the depths when i started my play through and I've gone so far as to beat the cathedral boss which seems to have broken his quest line as I was apparently supposed to kill the cathedral boss to complete his third request. After completing the second request he remains in the same spot and gives me the same standard dialogue over and over, I've left the area and even restarted the game but nothing has worked, I cant get the map and worse still I'm told the map holds one of the vestiges I need.

Is there anything i can do or have I just wasted hours of my time?

[Zeke & Sil]

The guides I've read for the maps don't quite match up with actual requirements, in my experience. See if there's any other sidequests you missed that might be locking further progression.

[Noco]

https://steamcommunity.com/sharedfiles/filedetails/?id=1951715961

Look's like you've missed something. It should work, assuming you meet the requirement's for the Quest trigger.

[TyresTyco]

How about killing the successor first ? Shouldnt be hard to grasp.