Just adding to your post. @PaQuilter1 sim and my sim are also in a friendship in my game. Their sports relationship is fine in my game. PaQuilter1's sim shows up in my contacts, in stories etc.
I did notice that sometimes I page sims to continue the relationship and they don't show up. I figured out they get stuck on the left side of the hospital with other sims there too. I had my sim travel to the medical center, click on the sim to continue relationship and bring them back to my sim house.
When I have added contacts not all stick. I don't know if it is because I have reached my cap on how many contacts I can have. I do know when I have to many contacts , scrolling through them is very sluggish
