Partnered Sims turn into siblings

Me too!

After the relationship tree update around Royalty and Legacy some of my married sims became siblings. I have tried editing the relationship in CAS, assigning both sims separate parents, and even downloading a mod to try and edit relationships. Nothing works, and the sims are listed as being sisters as well as soul mates. This is very upsetting especially since I have been playing this family for over a year. PLEASE allow us to edit relationships in CAS full edit mode again. I just want my married sims to be able to engage  in romance again without having to delete and recreate one of them, which will also delete all of their memories and history together. I am very disturbed and upset by this glitch and want it fixed soon please. 

Similar problem, but an entire branch of siblings in one family tree has this issue across different households. (ie Other families in this save are not affected.) All former spouses have been turned into “cousins” instead, but the romantic relationship bar is still present, as are romantic dynamics, soulmate statuses, etc.

The family trees still show children belonging to both parents, but married symbol is gone on the family tree.

No mods are in my game. 

I play on console with no mods whatsoever. A while ago, I reincarnated Mimsy alcorn shallott and had her marry one of my sims. They've had a child together, been married for ages, I think since before the latest patches. HOWEVER. As I was playing today, at some point, they ceased being married and became BROTHER AND SISTER, despite having a literal child together and the romance bar being fully in the pink. Mind you, minutes before this happened, they were doing normal couple things, until boom..... suddenly they're siblings. WTF. With the glitch that causes married couples to become unmarried and the OTHER glitch which makes Rebirth not work as it should, this game is practically unplayable now! I don't know if I'll be playing at all anymore since every time I do, another of my households gets screwed up! 

I did a little more digging, and sure enough, despite the big double wedding where both sisters got married in front of their wedding arch, neither was married. The households had been joined, but the game had forgotten the marriage relationship.

I went into CAS, copy-pasted a couple magic incantations so CAS would let me edit the relationships of pre-existing Sims, and made them spouses again. Now the family tree shows their new husbands, and in one case, the adopted children.

If it's any help in tracking this down, one daughter married a single NPC, and the other daughter married a single NPC who had previously adopted two NPC children.

Mac, no cc, mods removed and game reset.

This has happened to me too. My sims just got married and found out she was pregnant. They moved to a new house and all of the sudden they are half-siblings. I have dealt with this bug in the past and now make ghost parents for my single sims, but this time I only made the father of one of the sims. I probably would not be so upset if I had not spent literal days setting up my save and adding all new townies to the game. For the love of pete, can this bug please be fixed.

The two eldest daughters of my game's matriarch got married recently. I was curious whether the one daughter's step-son and step-daughter would appear in my matriarch's family tree, and was surprised to discover that neither daughter appears married.

The matriarch (Farrah) is at the top, with a green border and background. Her two eldest daughters appear on the left: Coralina (pink hair) and Celestina (dark hair). Both daughters should have husbands. Celestina has a step-son and a step-daughter, both adopted by her husband before he met Celestina.

Mac, no cc, mods removed and game reset.

My family trees are all broken within my game and can no longer be fixed by casfulleditmode or MC Command Center. They show son in laws as stepsons and suggest that wife and husbands are siblings! E.g. Don Lothario is classed as Bella Goth's stepson. Cassandra Goth's stepbrother but she has children with him.

This is a 10 year legacy save and it's so frustrating how much this has messed up. I have removed mods and it still doesn't fix the issue. This has been happening since the family tree was amended in an update and with each update I hope and pray it gets sorted. 

Please sims can you revert the family tree back to how it was when we didn't have issues? Or at least come up with a workaround where we can edit the family relationships ourselves as this really takes the fun out of playing this game.  

Please note that this is a machine-translated text.

These are my personal observations.

① Build Mode item "Family Tree Tapestry": Allows Sims to fabricate a family tree.

② Simology Family Tree: The family tree established by the player (based on their story).

Both ① and ② share the same underlying family tree platform.

The game's autonomous rules and controls regarding Sims coexist and conflict with the player's own settings.

That is why it appears that the recent update caused issues.

I suspect it will be quite some time before this bug is fixed.

Well, in my case, the game freezes when I open the family tree of a large family, and my Sims, who were married, are changed to single. (I have already reported this.)