A push notification that never arrives now says so

A phone can quietly lose its notification registration — after an app reinstall, an iOS update, or simply time. When that happened, nothing noticed: Settings showed a green Enabled badge and the test button always said it had sent.

Your device re-registers itself on any dashboard page, instead of waiting for someone to open Settings.
Settings tells the truth — whether this device is actually registered, not merely whether you once granted permission.
Send Test Notification names the outcome — delivered, no devices registered, or the server is missing its keys.