It appears since the release of iOS 13 on September 19th 2019 that APNS has introduced a new bug with the apns-push-type header that is provided when sending push notifications.
The documentation states that this header should be set to either 'alert' or 'background' depending on the type of notification.
I implemented this as described for my VoIP notifications, however APNS fails to send the notifications with an InvalidPushType error. This happens no matter what value I enter for this header, except for an undocumented value of 'voip'.
It also appears that omitting this header works as expected.
Please advise on the correct course of action:
1) Omit the header until the bug in APNS is fixed
2) Use a header value of 'voip' (undocumented)
Can anyone confirm that the APNS team is aware of this issue?
Thank you!