Currently, if you have a map displaying data, whether points or polygons, then if there is no data -- say because of a filter setting, the map disappears.
This is especially frustrating when you have pinned the map axes and have published a dashboard. Users don't expect the map to disappear, just because the current filter settings don't yield any data points.
Please make it an option to toggle whether to keep the map or not in this case.
The best workaround I've found (thanks to Joshua Mulligan in the forums) is to place a second map under the first so it remains visible when the top one disappears. (other solutions would be welcome)