Pages that are set to be region-specific or are for adult consumption (re: Alcohol products) cannot be found with the public API (as it cannot tell the region or age of the "user"). You can fix the region-specific pages by disabling their regions so that all users can see them, but the ones marked for adult users cannot be used with this connector at all and should consider using the normal Facebook Insights connector.
Instructions for how to change this are in the below link to Facebook help, under Privacy and Visibility Settings->How do I add or edit country or age restrictions for my page:
Also be aware that per the Facebook API, pages with less than 100 likes/followers are ineligible for Insights to be generated. So check the page's like count to ensure it means the criteria to have Insights generated.