Refer to the document: https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/handling_notification_responses_from_apns#3394529
Error code 410, 'Unregistered' means: The device token is inactive for the specified topic.
But since February 1st, 2024, we did not got 'Unregistered' response any more. Do you know why ?
It is expected that the 410 code returned for inactive tokens can be delayed. The 410 status is never meant to be an immediate response tokens becoming inactive, and there is an unspecified delay expected before 410 is returned.
If you are not seeing any 410 statuses right now, you should be seeing them again after several days. Sending notifications to inactive tokens until you receive a 410 return does no harm. If this is causing an issue for you because you are expecting a 410 status in direct response to an app being removed, I must note that the 410 result was never meant to be a signal for developers to determine that the app has been removed. It is actually a signal to the push provider server that they should stop using that token. Although this could mean that the app may have been removed, it could also mean the token has changed while the app is still installed. Trying to determine whether an app has been deleted or not, based on the 410 result is an off-label use that would not guarantee the results you might expect. Starting the return of the 410 state is non-deterministic for the sole purpose of discouraging this interpretation.