Households that I save in "other households" sometimes are suddenly gone.
ALT0420G As crinrict said, only sims in My Households in Manage Households are safe from being culled even if they are "Not in World". Culling only deletes entire households. It does not delete just one or two sims in a multi sim household. Culling will happen regardless of how many sims you have but imo, seems to happen more when you get near the max sim number you've set (80, 150, 200, Unlimited) so I suggest you set the max to unlimited if your system will handle it to slow culling down. Btw, only sims in the My Households tab are included in the max sims number. Sims in the Other tab are not. Since you use mods, MCCC had an option to bypass culling altogether, but it does have a downside in that ghosts will build up in the Hidden sims tab over time.
Another thing that can make sims disappear is Neighborhood Stories if you have deaths enabled so you might want to check your settings for that for both tabs in Manage Households. In this case, the game kills off only one sim at the time. If that sim was the last teen or above in the household, any children and below will disappear too.
Hope this helps.
