I am experiencing the same with my TestFlight build, was there any solution to this?

Do you have Multicast Networking Entitlement added to your app? Can be requested via https://developer.apple.com/contact/request/networking-multicast

Is there any change to this with watchOS 8?

iOS (16/17) and macCatalyst, same behaviour in each case.

Same issue on latest iOS 17 beta. Submitted FB12773661.

To resolve the same error I had to wrap all Live Activity related code with #if !targetEnvironment(macCatalyst) ... #endif