I have noticed this with my own parts. These offset outlines are usually misaligned DRC warning indicators.
I’ve found that this occurs with brand new footprints, but after they’ve been in the database for a bit, they go away. I don’t know too much about the back end, but this suggests that there is some sort of process deals with “baking” these details in.
It doesn’t look great, but it shouldn’t last long and will have no impact on the final result of your project.
Thank you very much!