After I killed Zuggtmoy and was teleported to Verbonc I was unable to interact with any objects or npcs. For example I couldn't talk to npcs or use the "blue door" icons. I'm running 8.10, the kicker is that my previous playthrough is still saved from 2015 including an initial Verbonc save and I had no problems with loading that one up and doing everything normally. I also left Verbonc on my current playthough and still couldn't interact with anything, restarting the game didn't help either. I'm guessing something got disabled during the slide-show? Probably just need to flip the active switch back on or something?
After sleeping on it, I thought it seems like it still has combat restrictions, and sure enough merely typing 'c' to enter combat and again to leave gave me back permissions to use doors etc.