Cannot activate Plateau map with Divine Vessel

Trying to start a Plateau (Puruna) with a divine vessel is failing to activate, claiming "Activation Failed. The boss in this map cannot have its Soul captured.".

Searching Puruna on the atlas highlights Plateau.

My current Brine King progress is with Tanner Lightfoot captured but nothing else.

Edit: Correct map is Atoll, bug is that searching Atlas for "Puruna" highlights Plateau not Atoll.