The APNs wake-up was sent with apns-expiration 0, so a phone without
connectivity at that moment (tunnel, flight) never received it and did
not learn about the message until someone opened the app. APNs now keeps
the wake-up for as long as the envelope stays in the relay queue.
Priority stays at 5: APNs rejects priority 10 for background pushes.
Immediate delivery on iOS needs a visible alert push handled by a
Notification Service Extension, which is an app change.
Julius Joska
414d39c835