When using the location proximity views filter, exposed with the "Latitude / Longitude input (use map)" option, the filter does nothing. It always returns all locations and doesn't filter anything.
As suggested in
The problem is there is nothing like:
$coordinates['latitude'] = (float) $options['latitude'];
$coordinates['longitude'] = (float) $options['longitude'];
in the location_views_proximity_get_reference_location() function in location.views.inc
so the lat/lon is not set.
This is a problem in all versions of location.