When a static mesh that already has sockets created in it's original third party program is reimported into the editor, it's sockets are duplicated. Going from 10 to 20 on reimport.
Results: Sockets on mesh duplicate when static mesh is reimported
Expected: Sockets do not duplicate when the static mesh is reimported
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-53635 in the post.