When attempting to reload the webpage while a map is currently loaded, Maps reloads to a “No Map selected!” screen. Asking all connected players to close their browsers before closing host browser and restarting does not load the previously loaded map, neither does it allow for selection of a new one. In essence, Maps is now unusable for this specific campaign. The other campaigns remain available for use as normal. 

I have the same issue, even tried clearing my cache and cookies and still nothing has worked.

Same issue. Any updates?

Following, same issue.  Maps doesn't work.