Sims forget already existing relationships

All of my households are forgetting every Sim they know every time I load into a household. I have them meet and befriend new Sims, rotate to a different household, do the same thing, come back and the same thing has happened, they only know the household. It doesn't matter how high the friendship bar is, they all disappear. It's making my legacy save completely unplayable. This has been happening since the November update. I don't have cc, the only mod I have installed is mc command, which is up to date and working and the disappearing Sims still happen when mccc is removed. Has anyone else had this problem? Any advice?