That must be a bug. I take so much time to go down to that prison - make sure, the owlbear cub comes to my camp, free Volo, talk to Abdirak, jam with some gobbos in the courtyard (there are some musicians among them and it sounds great).
I longrest as often as I like.
Did you leave the goblin camp area and came back? I would just load an earlier save as Ecc2ca said, I don't think, you have to go all the way bac kand start new
