I did some testing. What I found is that the camera will not drop down lower than the top of the basement wall for all venues that I tested except for residential. Residential venue lots work just like they do in all other worlds in both build and live modes and the camera will drop down inside the basement area. I did not test all venues, only those present in Nordhaven. I tested by placing a basement under each venue type except the lounge which already has one. I also tested various venues in two other worlds and those worked just like they always have with the camera dropping in down into the basements as one would expect. So, something is different about Nordhaven. While not a bug in the classic sense since it doesn't break game play, it shouldn't be happening and is probably something that wasn't intended by the designers.
Hope this helps.