Partnered Sims turn into siblings

Having the same issue here. Household started as a brother and sister living with the sister's spouse. (When creating this family originally, I duplicated the brother from the sister to create the household). I moved the brother out to a new household, but after the Feb 3 update when I loaded in, the sister and wife are now listed as siblings but still married with 3 kids. Kids relationships are normal to their parents and each other, but after playing for a while the couple is now no longer listed as married. MCCC let me reset relationships between all 3 people but that only lasted a minute and then reverted back to siblings. Same with changing the spouse label through MCCC; only lasted a minute and was removed by itself. Thinking the last user is correct in that the issue is stemming from sims who were duplicated to be created (an incorrect listing of siblings / siblings-in-law).