I had a similar thing happen in 2 quests so far in 10.7. I also have DREAM and I have DFU Quest Pack #1. Plus the Enhanced Objects, I forget its exact name, but very common download.
Anyway, in my most memorable one, I remember this much. The Quest Giver only mentioned to talk to 2 NPCs, to find out where a certain lady was who had not returned home. The People list on local passersby had 3 NPCs listed, not including the Quest Giver. That's odd already, as it suggests that all the key NPCs to a quest may be already known to locales and being set before I even advance the quest.
Anyway, the Locations list mentioned 3 Buildings, which was also odd, since I should only know of 2 NPCs to ask, so 2 buildings.
Ended up that one of those buildings had another NPC who knew of the quest but was not guilty. 2 of the 3 People NPCs were in one building.
One of the things I noticed is that the names of Residences like Wicking or Wickham etc seem to be spawned by the Quests. After you are done with the quest, the name on the building is gone from the town map. One of the things I had been doing also beforehand, as I got tired of talking to the locales and being despised so getting no info, was to just click with info mode on many buildings -- I was hoping to find the various key named buildings having Family Names or whatever on them.
That's when I noticed that the names can change and even move from one building to another. So during a Quest, one building may be called Wickham Residence, but after quest another might be called that. Not sure, but I think the original Wickham is then removed.
But it did seem that some buildings have names on them beforehand, like sometimes Buckingham. But I might have had another quest not yet progressed as well at the time.
So maybe the name for buildings is not being released or corrupted, especially if you have several quests ongoing. The other big issue is that there are lots of very similar names, not just for buildings but for people. Like I had two Theodores to chat with in one quest. While I also had in several quests a Andore this, but in same building of target there was another Andore with a Y in the start of second name, which was not the right person. Same with Buckingham residence, there is another one with a very similar name.
Anyway, hope you have figured out the problem, but I gave up on at least one of these if not both. I'll have to be more careful next time I get one of these and make multiple saves.