I may be seeing a similar issue. A few customer devices are getting this error on every WeatherKit request. I can't replicate it on my own devices, but I'm telling customers they should just request refunds because they can't get the service they are paying for. This is my post on the topic. https://developer.apple.com/forums/thread/789319 Did you ever find a solution for your dev device?

I've heard from two affected customers that the problem has gone away. I'll be reaching out to other affected customers but I'm cautiously hopeful. I've been working furiously to set up a API proxy server to route calls from the app (thereby using the REST API on my server, and potentially getting rid of WeatherKit entirely). I still think I want to finish that work so I can have some insurance in case I need to suddenly switch weather providers. With a proxy server I can do that without a binary update on the App Store. The WeatherKit SDK is very convenient in how it doesn't require a proxy server to secure the API key, but this failure from the last couple of days has me spooked (especially given no acknowledgment from Apple that there was even a problem, and nothing ever showed up on their status board as far as I saw).