[ARCHIVED] Partnered Sims turn into siblings/family relationships

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 1.63.134.1020
What expansions, game packs, and stuff packs do you have installed? All except ROM and Vampires
Steps: How can we find the bug ourselves? I honestly don't even know but I have a long standing family that has reached the 4th generation and I don't know if you need that deep of a family tree or what but you need a family of sims.
What happens when the bug occurs? My family tree keeps getting broken a part. It keeps disconnecting my sims and then it goes and reconnects them wrong or swaps them around or completely removes them from the family tree.
What do you expect to see? I expect the family tree system to be fixed and reconfigured a lot better than what it is right now.
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes
Did this issue appear after a specific patch or change you made to your system? Yes
Please describe the patch or change you made. I have no idea. I've never had an issue like this with the family tree until recently.

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I don't know if it's when I go into CAS but I have a feeling that CAS has something to do with it. The game keeps making my married sims, siblings to each other. When I hover over them in the relationship panel, it will say, soulmates, spouses and brother/sister. No, I do not have a mod that allows for that weird family nonsense. My sims aren't into that kind of thing so naturally, I'm highly annoyed by this. Every time I change it, the game changes it back and I don't know why. Even using a mod to fix the family tree doesn't work. It just disconnects them all over again and reconnects them again incorrectly. It removed my male sim's mother from the family tree. Instead of her being there, it's an empty image. She is the grandmother to his kids and sometimes that doesn't even show up when I have the kids hover over her image in the relationship panel. It made my male sim's wife his sister and I've seen issues as deep as it removing 1 or 2 siblings from his wife's family tree and making them half brother/sister to each other. The other thing is, it'll disconnect the sims from the family tree but when you hover over the sims in the relationship panel, it'll still say they are the parent to a child that the game removed from the family but it'll remove cousins, aunt and uncles and so forth. This glitch goes so deep. It's frustrating. I've been messing with this for over a month now and it's really pissing me off. I have never felt so strongly about being done with The Sims this much all bcus the family tree keeps messing up. I'm really annoyed and I hope more can be done aside from saying there needs to be more input. There needs to be some major work done to the family tree system. This is truly disappointing and disheartening. I don't know how else to fix this.

This issue does this throughout the family tree, not just with the current sims I'm playing. The images I posted show my male sim married to his wife but it also connecting him to the rest of her siblings, making him also, her brother. The tree will also show you that he doesn't have a parent. The game removed her from his tree but in the game it still says she's his mother. I don't know what better way to describe this mess.