Sims Disappear from Lot After Exiting and Reloading Save in Hobby Lot

Whenever I am on a hobby/community lot (specifically the one where Sims learn the Writing skill), I exit the game and reload the save. My Sim loads correctly on the lot, but my Sims are missing. They are not on the lot, not at home, and not visible on the travel map. It feels like they went to work, a social interaction, or some unknown location (even though they’re supposedly at the current lot).