Only Host can do quest and get to Zurberer

I play with my friend on the game and we've been trying to go after the last boss. But, only the host has the quest and thus they're the only ones with the ability to go to the "Biodome" and fight in there. We've tried everything from reseting quests to trying all different beacons but it seems at this time we can only try to solo the boss. Is this supposed to be the way?

This goes back to my discusion earlier Hero, quest line is bugged still for infestation quest, which then breaks the bio dome.

I can fix it.