The house is filled with both photos and paint by refs, as one of the residents was an explorer. I didn't know those were triggered as CC.
When you say no mods, do you mean in the save itself - or cc in the house? I know from experience that removing all mods from game usually temporarily solves the problem, the issue is that when I turn mods back on, the problem reappears (so yes, in some way mod-related, some conflict that I just can't figure out).
All mods are updated, and none have to do with lot types. Also everything else in the game is working as it should, but not that one lot (which is the only without cc, the ones with lots of cc works just fine).