I tried several times and they all 4 teleport to the tavern when I go there and they are all removed from the passenger list. The only passenger that remains is the prisoner, because there were originally 5 passengers where 4 of them were the missions, and one is a prisoner that still remains.
Viewing post in Passenger does not disembark.
It took some experimentation, but I found the problem. It works fine if I fast travel to the tavern, but if I walk through the side door, then Froyla does not appear and he remains on the ship. I fixed the problem and updated ERAS. The same problem exists in COAS and GOF too, so I fixed it in all of them and now, if you walk through the door, the extra passenger appears in the tavern; the problem exists because of a lack of sufficient "goto" locators in the tavern for a larger number than 3 passengers for the same tavern location.