BUG - Atlas Tree Progression

Hello,

I have killed arbiter of divinity 5 times now, all the maps are completed in the fortress.

I am still missing 15 atlas point, and I can't allocate the top nodes behind the "Defeat Arbiter of Divinity" node. The only thing I have is the quest Arbiter of Divinity - Collect the Divine Power but there is nothing in the Arbiter room to interact with or anything.

I can provide screenshot if needed.