My Sim keeps dying every time I go to a different household

As a multi-household player, I often switch which Sims I play with. I don't have any mods or cc installed. Whenever I go to a different household, I get the pop-up that the same Sims has died when there have been no issues in the family. I normally go back to the main menu and reload the save. When I go back into the save, the same sim dies again.