Completely Stuck in Caravan Progression

I'm completely stuck in progression of the single player content. I have reached 6 Star quests with the caravan, but there are no more quests offered to me.

I would provide a screenshot if I knew how to make one. My situation is this: I did all the quests offered. But the check mark on the 6 Star quests is only silver, indicating there are undiscovered quests left. I have checked every location in the game, but there are no more speech bubbles.

What is strange is that the box for the urgent quests is still there, with two quests, both checked as well, I have done both.

So, did I miss something? There are no more hints in the game, and after searching in the net I seem to be the only one having this problem.