I created a structure using the "Empty Structure" wizard workflow. This allowed me to include features in my structure. When I am in the structure and create an epic I mark the correct feature as its parent, but when I save the epic the parent link goes away and I have to re-add it. When I do that, the epic now shows twice in my structure. Similarly, when I add a story and add the correct epic in the epic link field of the story and save the story, the epic link goes away. When I re-add it, the story now shows twice in the structure.