Did you ever find a solution? I am running into the exact same issue.
Hi Joseph,
Yes in my case, I fixed it by making sure that whenever I am navigating away from the page (or hiding the panel) I unload the map (call the map object Destroy method), and when I am navigating back to the map page or when I need to show the panel again, I reload the map (calling the function that init and load the map)
HTH
Jafar