See attached .blend file.
There is no relationship defined between plate stand GN and plate.002 but whenever I link or append the asset plate stand GN the other object always comes along for the ride.
Plate Decorative.blend (679.9 KB)
In the file you send there is the relationship between them in the default field of the object group input.
But only removing it does not help. It seems blender does not remove the dependency correctly. To get get rid of it you have to delete the input and recreate it together with all the links.
Made a bug report.
Thank you. That was annoying me so much.