Sims won't stay married/relationship reverts back to Partner

So as the title says, my sims won't stay married. As soon as I enter CAS, their relationship reverts back to Partner. I can make them married again using cas.fulleditmode, but it doesn't stick and reverts again after entering CAS, plus they also get Just Married moodlets like they were never married. I've also noticed that only 1 sim will get the milestone Got Married, the other sim never gets it. This is what I've tried to fix it without success: no mods with cleared cache, brand new save, different households, brand new households, sims living in the same house and sims living separately. I haven't tried repairing yet or reinstalling because I'm on game version 1.125.59.1030, and I really don't want to update yet until the issues with the new update are resolved, but I also can't blame this on the new patch. Just wondering if anyone else is having this issue, I looked and I can't find anything. 😞