Missing Family Member Bug When Visiting Community Lots

I have a problem where one family member is missing.

My two adult Sims, created in CAS, have 3 kids in the game. The first time I encountered this bug was when the 3 kids grew up to teenagers, and I let them visit community lots in the neighborhood or downtown. When they returned home, one teenager was missing.

I tried to solve the problem by inviting that teenager to visit the house and using the cheat boolProp testingCheatsEnabled true. I then selected MAKE SELECTABLE to make him part of the family again.

Everything seemed fine while playing in the house, but as soon as they left and returned, the teenager would go missing again.

I used the cheat to make them selectable again, but this time, I let him visit a community lot alone. When I tried to send him home, he couldn't return. The taxi arrived, the sim disappeared from the screen, and nothing happened. The game remained stuck at the community lot, with no loading screen to return home. I couldn't do anything and had to exit the game without saving.