@jessicaand481 Unfortunately I was unable to reproduce. I tried placing a restaurant I have made previously that has a sunken room, plus I tried adding a building with a foundation then two sunken rooms with one being in the corner like yours, and still cannot reproduce. (Please see my screenshots.)
Something I could not reproduce was the foundation color in yours, which looks to me like it may be unusual. Can you please tell me then name of the foundation that you used on your building?
Also... can I please have you try the followwing to see if it makes any difference?
Delete the localthumbnailcache.package file in your 'The Sims 4' folder and restart the game and so that the game will re-create the folder.
Then run a game repair [ Open Origin, click 'Game Library' then right-click Sims 4 > Repair Game ]. Make sure to let it run until it has completed all repairs (it will do the base game first, then run through each of your expansions/packs).
Can you please upload your build to the gallery so I can test it in my game? Once it is in the gallery please share here the exact name of the lot and your EA ID / name in the gallery. Thank you!
