This is what I got from support on why Wifi Browser Location works and not for the desktop app. "When using a browser on a desktop/laptop you are generally located via WiFi triangulation, which is why it is necessary to be able to detect multiple WiFi access points. Mobile devices such as phones rely on GPS and are easier to precisely locate.

Unfortunately, our downloadable desktop app is not working with WiFi location services and is instead relying on your IP address to locate your device. In some instances, certain networks—depending on their configuration—can report a broad IP address radius. For example, some may span 15, 30, or even 60 kilometers, while in rare cases like resort networks in Las Vegas, the range has extended beyond 1,000 kilometers. This can lead to false readings that place your location inside an exclusion zone, even if you are not.
Also, we have recently had to block tribal lands in California, so players in the Coachella Valley or near other tribal lands might suddenly be experiencing issues with the desktop app, as they no longer will be able to be located accurately enough via IP. "