Cannot set parents for pre-existing sims

Can you place them in the game and check their family tree ?

I did that and the children still only have one parent. The other is listed as step-father. 

One of the parents has a faceless, nameless parent of his own showing up on the family tree and only when I'm on his children's genealogy, not his own, even though I don't remember ever giving him a parent. I doubt that would be affecting this issue though.

Would you mind uploading them to the gallery and post the name here ?

I eventually found a fix, but they are uploaded as "Bale's Broken Household" if you still want to check out the bug.

The kids originally had two parents that I deleted and tried to replace with two new parents. I discovered that if you change the kids' relationships with the original parents to "Household Member" before you delete them, then you can give them two new parents with no problem.

Hi Builder_Belle​ 

Yeah sounds like the game still thought they have parents, so basically also the the phantom parents issue. Just curious that they didnt' show in your family tree.

EDIT: That household you uploaded shows them with the correct parents ? Did you upload the correct household ?