I have unlinked a child from its parents and linked it to the correct parents. (It was only the mother was wrong.) Now when I view the descendants of the parents, the child is shown twice, although the child appears only once in the list of people in my database.
I would add an image but can't fathom out how to do so...
Edit: Forgot to say it v 7.5.3
On further examination, I think it's being over-kind to say that it partially works.