Sling TV Geolocation

Yet another geolocation post, because content networks don't pay attention to geofeeds... :-) Anyone know who Sling TV is using for geolocation, or have a contact at Sling that can help? We acquired a /19 in July that we just started pushing out to customers, it is still geolocating back to the previous owner on Sling TV, despite publishing the prefix in our geofeed. Checked the usual lists with no luck. Thanks, Tim