Hello, I'm in a similar situation and would also like to change my forum username. Thanks!

As of iOS 17 beta 4, WeatherKit appears to be returning data for the daily WeatherQuery again on device. In previous betas this always returned an empty array for me, but did not produce an error. I'm also no longer seeing the com.apple.weatherkit.authservice error when building in the simulator with Xcode 15 beta 5. THANK YOU, WEATHERKIT TEAM!