Same here... it worked in the betas, but stopped working now that I want to publish :( Weatherkit is enabled in both Capacities, and in the App Services...
I have decoded the JWT token and ensured it contains the exact same items as the sample token at https://developer.apple.com/documentation/weatherkitrestapi/request_authentication_for_weatherkit_rest_api
{
"alg": "ES256",
"kid": "3J4F34**24",
"id": "KC697SNQ2X.com.caramba.instaweather"
}
{
"iss": "KC697SNQ2X",
"iat": 1437179036,
"exp": 1493298100,
"sub": "com.caramba.instaweather"
}
response is
{"timestamp":"2022-09-16T18:17:15Z","status":403,"error":"Forbidden","message":"Access Denied","path":"/api/v1/availability/37.323/122.032"}