I was able te reproduce the problem. If you have the 'filter type' set on 'location' then it won't show anything. At least, here. But your preferences do not produce an empty result here.
Maybe check the preferences page where you can edit the custom fields. Because you are retrieving from the names on your server, the correct fields must be used in order to display anything.
Could you try an custom application to see if the app works? You can connect any application as long as you connect the fields in the preferences page.