PushKit (fileProvider) calling didInvalidatePushTokenFor instead of didUpdate (credentials)

I think I've got all the keys and entitlements set up ok. I have no problem receiving normal alerts via the UNUserNotifications framework. Now I'm trying to use PushKit (for fileProvider). I have the following in my AppDelegate fileProvider = PKPushRegistry(queue: nil) fileProvider.delegate = self fileProvider.desiredPushTypes = [.fileProvider] along with the required delegate functions. I am never provided with credentials, only an immediate call to the didInvalidatePushToken delegate.

Any suggestions appreciated.