My family in the sims four is disappearing

So I have this family in the sims four and it’s the only household I have fun playing. (I don’t know if this helps you fix this but they are mermaids) I have two married young adults that got together as teens. They also have a toddler. This family has disappeared before when one of the young adults was a teen who lived with her mom. I they live in the pure perfection house in sulani and I have edited color and shape of this house for them to live in it. When they disappear the houses color and shape goes back to the original one and you can’t find their household in load game. The first time they got lost I just restarted the game and they were back but they have been gone now for two days. I was able to find them in the gallery but it’s an old version of them where one of the young adults was a teen living with her mom. I can’t find the wife, kid or young adult version of this sim anywhere and I can’t find there house that I made PERFECT for them. Has anyone else had this problem?? I’ve been looking at all of these family disappearing ?s but I can’t find one like this. EA please help me!