can't change relationships

I'm playing on Xbox One, with a family of 3 cats, 2 children, and 2 adults. I had duplicated this save so I can change the father sim in the household without changing it in the original save. I delete the father sim of the two children and add the new father, except it will only let me change the relationship with the other adult sim. I made it so they were married, however, I was unable to change the relationship between the new father and the kids to father and daughter. I did this in manage households. I decided to play the household, then typed testingcheats on and then cas.fulleditmode and went to cas, and was still unable to change it. I tried this cheat: relationship.add_bit yoursimID targetsimID family_son_daughter and it doesn't work. I made sure the cheats didn't disable, and tried it again, but it still didn't work. The new father sim was made on another Xbox profile and then I added him to the household from my main Xbox profile, if that does anything. I never saved him to gallery first, just added him to the household. I don't want to have to delete all of the sims an readd them from my own gallery since I'm afraid it will remove all the friendships I had with all the other households in my world, along with celebrity perks/squad, etc. Anything I can do to fix this?