Having created some user stories I would like to visualize them afterwards in the board of the backlogs in Visual Studio Online. I haven't found a way to add an existing user story to the board. The only way to visualize a user story is to start a new from withing the backlog.
Is there a way to add an existing user story ?
Have you ensured that your existing User Stories have the correct Area Path and Iteration Path? It might be good to compare the values for existing items vs. new ones.