Sub Structure duplication is borken
When you duplicate a substructure of a structure (fot exemple of the DDB) and you drag the duplicated substructur into another structure (for exemple the DSC launch pad), some parts of the substructur aren't well moved and still are in the previous sutructure.
In this exemple, the doors are still on the DDB even the building is on the DSC launch pad.
EDIT : This bug also appear whith non-duplicated substructures
@pedro16797 i haven't selected any part. That's weird, because in fact the substructures is automatically put on the launch pad when I switch it from the DDB to the DSC launchpad