I'm having the same problem after upgrading to the AW4. While my iPhone is connected via bluetooth or wifi (wireless CarPlay) using my AW sometime will just say, Siri can't connect using the iPhone or AW. I mostly use it to navigate music. Like "Siri, play playlist Beatles" things like that. Really frustrating as my AW3 worked well. I've tried resetting my AW several times, but it seems the problem always comes back.