I don't really have any way to verify if it's a bug here. Part of the game is revisiting the information you have and being absolutely sure about everything. For example, you might have all of his information right but not have him in the correct spot on the tree. Sometimes people have similar names, etc.
If you'd like a hint for as to why it is incorrect, we can help in the discord without spoiling anything. There's a link on the settings menu,