Couch Co-op progress problems

In act 2 my couch co-op partner is behind me in progress and has the quest to travel to the halani gates after mawdun quarry, but is unable to travel to traitors passage/halani gates on the desert map, as if she hasnt killed rudja and brought the defector back to the caravan, theres a wierd interaction with player1 being ahead in the campaign then player 2 causing player 2 not to get all map progress or something?
im not entirely sure what is happening here but something odd is going on and needs to be looked into, GGG was very excited to bring couch co-op, knowing them they want this to be perfected so here is a small blip in the couch co-op world, anybody else similar interactions?

It seems that if you are not on the same quest progress with both characters all manner of problems happen. For example if one character has completed Una's lute the other will never find the lute (chest is empty) as long as you coop.
A workaround is to temporarily use only the problem character to complete/advance the quest. Then you can switch back to coop.

In your case, log only on that character and try to travel to traitors passage/halani gates alone. After that switch back to coop.