This is pretty sad. Zahrah Benali Mahi'ai is a descendent on her Mother's side of Salim Benali from City Living and on her Father's side Nalani Mahi'ai a Mermaid from Island Living, plus other Sims probably NPC's I adopted and played over the years.
Eric Park is a descendent on his Mother's side of Olivia Kim-Lewis from the Base Game and a host of Sims - also probably NPC's because I very rarely make Sims - that I adopted and played with over the years.
As you can see they are have no parents - no ancestors at all. No relatives, except their kids. And yet their Families have run through my game for years.
I do play a very long rotational game. It does take me a long time to get around to all my households. And, long ago, I stopped trying to keep time lines and relationships straight, but this is a pretty messed up Family Tree. But, it may be that the way I play has messed up the data the Family Tree system is looking for. 🤷♀️
Adding:
Obviously Cornelia Goth is a Goth. Yet no Parents. No Ancestors.
Xzavier Larkin is the son of some Sims I actually made myself - Dave and Eve Larkin - for a test game. I liked them so, I moved them into my regular game. But they don't show up as his parents.
I've had a "Cemetery" (used to be a park) in my game for quite a while. Xzavier's parents are still there.
Most of my Sim's Profiles still show their Family relationships: Aunts, Uncles, cousins etc.
Except for the Ancestor losses on the Family Trees this - so far - doesn't seem to have impacted my current gameplay. It does seem sad for all those players who've invested years of play in big complicated families. Or Legacy players that have kept track of family heirs through multiple generations.
