I play on PC, nocc, & this has been an issue for years😔. I used to think it was moo cheat causing it since I usually use it; except, found out that's not it, because I just built a home without any cheats, and it still did it to 3 windows on the build. As usual, I selected the window, then pressed esc to undo it, to make window good again, but as a builder, it's very frustrating that this hasn't been looked into properly by the Sims team yet.😮💨. Years. Y.E.A.R.S. 🤨.. soooo, tbh I don't even know why I bother wasting time signing in to comment on this in here, because the way it's going, doesn't look like anyone there intends to fix it, ever, among many other bugs sadly😞.🤷