Problem Attaching Parent

For some reason, a father has become detached from one of his children. He is still attached to his wife and other children. I tried attaching the man to the child from the list of people already in the file. The person appears and I have chosen him. However, he does not actually attach. I have tried 3 times, thinking, perhaps, that I forgot to do something. I keep striking out. Is anyone else having this issue?

Display the parent in the Family View. With a parent highlighted click on Add, Add Child and then “Select existing person”. This will make sure the child is added to the correct family group.