PBS uses GeoIP localization to try and match you to your local station when you use PBS websites and apps. The system looks at the location of the source of your internet provider which, in some areas, can come from pretty far away (especially cellular networks for mobile devices). As internet providers run out of IPv4 addresses, they supply IPv6 addresses which do not geo-locate well. Click the following link to see the location at which your IP address is being picked up on the device you are currently using: https://www.maxmind.com/en/locate-my-ip-address. Look in the Location column located in the table at the top of the page.
Changing how PBS localizes viewers requires a major system-wide change, so there is currently no solution. Please be on the lookout for news regarding localization enhancements.
In the meantime, click here to learn how to manually change your assigned station with PBS.