If I add one or more asteroids to an observing list, and then Update Minor Body Orbit Data (in Settings->Solar System), all the asteroids in the list change to different asteroids.
I created an observing list and added asteroid (424) Gratia to the list.
Then, I updated minor body orbit data.
Then, I looked at the observing list and it contains only the asteroid (460) Scania.
So, the asteroid I added to the list has changed into a different asteroid.