Hi, I have a sim couple with 7 kids. I originally put them in a house with the mom's parents. I switched and played a different family for a while before seeing on map view that the family had been split up, the couple and their kids moved out of the house with her parents. I just left it and continued playing other families.

After a week or so I saw where the grandpa passed a way and the grandma was living by her self in her large house. I thought it would be a great time for the daughter with the large family to move back in with her mom so the grandma can help raise the kids. So I used MC add sim and moved the couple and their kids back into the grandparent's house. I made sure there were enough beds for everyone including cribs. I have MC settings allow more than 8 sims per house set to true as always. So I then switched families again. I look at their house in map view however and see once again that the extended family has been split leaving the grandma to live alone again.

I think it must be SP causing the move but when I check the SP >Town Options> Max Size: Humans currently still set at 8, I question if I need to change this because the description for these at all levels say it is to control how many sims "this mod" will stuff into a family. And Since I don't want the mod to make overstuffed families I hesitate to change that.

I think I can change the SP settings on the Lot level to prohibit all moving after I MC> add sim to put them all back in the grandma's house, but I think that might stop the kids from moving as they grow up also, which I don't want.

What have I missed? What should I do?

You have to change the SP option if this household is ever to be not the active one and stay together, but it's not necessary to do at the Town level. You can do so at the individual Household or Caste level.

The only thing the MC setting impacts is player-directed MC commands like Add Sim (as well as MC > Adopt, Pollinate, Instant Baby). What becomes of the household when it is not the active one is up to SP. If EA's story progression had been in charge instead, that household would have been undefined and likely some or all of the sims would have been culled from the game or some horrible thing like that, but fortunately we don't have to worry about that scenario.

Thanks, I will change it at the household level.