PS5 here, I've had this during builds too, the worst time it strikes is after spending about an hour figuring the floor plan out and I forget to save for along while, I've had it on multiple lots/saves and it seems to strike after putting roofs in, especially ones that overlap/go into another roof, just this morning I experienced it but only lost half an hour of building time but I hadn't saved since I put down my first wall so that builds gone, in my experience I go into the save game menu, I can press a save file to save over, press ok, but then it doesn't actual save, closes the menu and goes back into build mode then I reopen the save menu again and I can't click anything.
I use a keyboard and mouse so unsure of the controller buttons but this sounds much like what I have at times :)
The Sims Team
