Sims children who die dont become ghosts

I had two twin sim children who perished in a fire. They were reaped by the reaper and the pop up option came up to choose if they will become playable or freeroaming ghosts. When I selected playable ghost, their urns appeared but they just respawned, alive. Family tree does not say deceased, needs are not changed to ghost needs. I restarted, let them perish in the fire again and chose freeroaming ghosts this time. They vanished from the household, still alive, but with no urns this time. They are still alive and are aging up outside of my household.