Relationships Reset After Moving Household out of My Households

In my main game, I have a bunch of households that I've made and played with a bit. I try and form relationships between different households so my sims can have friends. However, once I finish setting up relationships, milestones, etc. I move the household out of My Households to Other Households just to keep things simpler.

Recently, I went back to an old household that I had moved to Other Households and saw that all of their relationships were gone, aside from the family ones. I looked at some of my other households and the same was true. Their skills and jobs stayed the same but all the relationships were reset. Does this happen when you move a household out of My Households or is it just a glitch in my game?

There isn't much I can do about it now, but I'd like to know going forward 🙂 Thanks!