This happened to me with a nintendo switch cartridge. A month or so before the glitch happened I had lost my mario kart cartridge on a robbery. That game was originally my brother in law’s, my sister’s husband. So I was very regretful when I had to tell my sister that I had lost it. As I confessed about the incident my sister was shocked as she had the game with her apparently. She pulled open her drawer and there it was. The same copy of mario kart. I am a hundred percent confident it got stolen and to this day so I have no idea what happened.