POE 2 couch coop - can’t access Act 3 cruel anymore

Hey
We can’t access act 3 cruel anymore
But we can access Act 1 & 2 cruel

It’s very confusing as to why specifically act 3 cruel. That means I can’t finish the campaign.
I’m at the Matlan waterways and everytime we login together we are sent back to ziggurat encampment and the waypoints don’t show so we can’t travel there.
Is there anything we can do ?