That seems to just show map #2, if a lat/lng custom field is present, so it would show whatever was saved in map #2.
Are you also using the ‘geocoding’ settings to generate a map in the post? If so, you can configure a field for lat, lng AND poi title, and the generated map should use that title. If you’re not using this already, please see the documentation for details about setting it up. You can use your existing custom fields and existing posts – just update the posts to generate the maps.
Mashups autocenter so all the POIs are visible, so the center argument will be ignored.