You are not logged in.
Is it a known limitation that the drill-down url isn't followed
when the top-level map data are defined via map_data variable?
When clicking on an area with a drill-down url,
the map is refreshed, but the data remain unchanged.
The drill-down URL isn't even visited.
The drill-down works, when the top-level map uses data_file variable to define the map data.
Thanks for reporting. We'll look into it.