We provide users with an iOS app that sends VoIP notifications. However, we received issue from users that "VoIP notifications were not sent." So we conducted an investigation on-site and sent VoIP notifications more than 10 times to about 20 devices. We confirmed that most of the notifications arrived, but there were also times when the notifications were not sent. We would like to know if the VoIP notifications were really delivered to the devices that did not receive the notifications. If this phenomenon is a network problem, we would like to consult with the network company. We have attached the log of when we checked and the VoIP notification was not received. logs [2024-09-12 11:50:02] 'ApnsId' => '22541A6E-355E-73D6-D28F-D1F8E340E540' 'StatusCode' => 200 [2024-09-12 11:50:02] 'ApnsId' => '22541A6E-355E-73D6-D28F-D1F8E340E540' 'StatusCode' => 200 [2024-09-12 11:50:02] 'ApnsId' => '2984C9F3-CC81-9080-7B54-EF53D2E77D68' 'StatusCode' => 200 [2024-09-12 12:43:01] 'ApnsId' => 'A936595B-36F7-07C2-CFB7-3276C4BE8FC8' 'StatusCode' => 200 [2024-09-12 12:43:01] 'ApnsId' => '0C633C08-25B0-6FE2-2087-DD66C1C01532' 'StatusCode' => 200 According to these, the status code is 200. We would like to know if the VoIP notifications in the logs shown above were received by the iPhone device we tested.