My Sim wives are now sisters

I have no idea what happened, but my 2 female Sims who are wives are also now apparently sisters??? I don’t use any mods apart from **bleep** and I’ve never had any other problems with other sapphic couples on the Sims ever. This is absolutely ridiculous and I have no idea how to solve it. Also very apt during Lesbian Visibility Week.

I’ve also seen that this is only happening with same sex couples which is absolutely aggravating. I’ve downloaded MCCC to try and fix it that way but even that is not working and I don’t want to mess anything up as my couple has 3 kids together. I’ve spent so many hours working on this family and I am actually devastated.