Lot with no CC incorrectly marked 'Modded' when Saving a Lot

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? so far, once
What expansions, game packs, and stuff packs do you have installed? All except Cottage Living, Vampires, Realm of Magic, Strangerville, Journey to Batuu, My First Pets Stuff Pack, Toddler Stuff Pack, Romantic Garden, Luxury Party, Bowling, Movie Hangout, Spooky stuff.
What happens when the bug occurs? I do have CC installed, but I was building a "every room is a different pack" build, so I did not use any CC, only respective packs + some basegame to make the build functional. When I went to save the lot, it shows up automatically as modded. I went back and made sure that I did not have any "hidden objects" or gameplay unlock objects placed. Weird thing is that I tried selecting each room individually and saving them, none of them got the error, i.e. were not flagged as including CC. With the rooms tested, I deleted everything on the exterior to check if any of those objects were the problem, but when trying to upload the entire lot, it still showed up as "Modded". Tested on uploading another house with random objects on another lot, the bug did not occur.
What do you expect to see? When no CC is used, the 'Modded' section on The gallery isn't auto selected.
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes, but no CC was used in the build and other lots that I tested don't seem to be impacted.I also haven't changed my mods in quite a while and never had this issue before.
Did this issue appear after a specific patch or change you made to your system? No