Just started working for me today!

I'm also getting a 401 response code. I've tried running the demo code on Mac, iPhone (simulator running iOS 16), and iPad (physical device running iPadOS 16). My App ID configuration in the developer portal has WeatherKit checked in both "Capabilities" and "App Services". My Xcode project has WeatherKit added as a capability in "Signing & Capabilities". I've waited an hour since setting up my App ID in the developer portal. I'm not sure what else there is to try at this point...