Random Relationship?

I started playing a family, and my main sim is now a teen. Ever since she aged up, it has said that she was in a relationship. There is not a single sim in her socials that has a romantic bar with her. Today when I launched my save, a notification popped up that she was engaged to this mysterious sim. Again, there is not a sim that she has a romantic bar with at all. After some investigation, this sim isn't even in my current save at all. 

For relevant info, I do play the game with MC Command Center and UI Cheats. I have played the game for years with both mods and this is something I have never dealt with before. 

My biggest concern is that since I can't access the sim that my current sim is in a "relationship" with, I can't break up with this random sim, so I'm worried it will affect my gameplay.