I noticed this too when I decided to play The Sims 4 on July 27, 2024 (Saturday), after hoping that the 2 hotfix updates they released would mean The Sims 4 is fine to play now, but NOPE!! After finishing with CAS and building the house to my likings (and saving afterwards), I was ready to do my usual thing of taking screenshots, until I realized that the ceiling look weird. Then I decided to do some research online, only to find out that it's a widespread problem that apparently WASN'T fixed! I actually kinda went into tears when I realized this, and now I'm STILL waiting for them to fix this because it's such an eyesore, making it a problem for Simmers who take lots of screenshots when playing! I don't think I've ever been so frustrated about a Sims 4 bug before!
I will note that what I did that day will be a head start for my Sims 4 Session, so it wasn't necessarily all for nothing.