We've observed a steady decline in the number of responses to APNS requests coming back with the "Unregistered" reason. Since about the beginning of 2022, we've noticed that "Unregistered" responses have dropped off altogether for the oldest device tokens recorded in our backend. Going by the APNS response status, it would appear we're still successfully sending messages to these very old device tokens, but this seems counter intuitive. We would expect the opposite, that over time those oldest device tokens would be the ones most likely to no longer be active (i.e. app uninstalled, devices no longer in use, etc.). Many of these devices tokens were recorded years ago, so we find it hard to believe that none of them would be inactive now. Does APNS stop providing meaningful response status for device tokens at some point? For example, if the device is no longer reachable (not working, never powered on or connected, etc.), would a request to send a message to that device still have a "Success" response? And if so, is there any way to determine if those device tokens are truly inactive or not?

Over the past few hours we've been seeing errors when attempting to connect to the APNS Sandbox push service using the HTTP/2 provider API. We've confirmed out push certificate is valid and for the correct topic/app ID. I've tried following the troubleshooting steps here: https://developer.apple.com/library/archive/technotes/tn2265/_index.html#//apple_ref/doc/uid/DTS40010376-CH1-TNTAG31 When I test out the TLS/SSL handshake with OpenSSL, I get a handshake failure error: 139925350537104:error:140790E5:SSL routines:ssl23_write:ssl handshake failure:s23_lib.c:177: --- no peer certificate available --- No client certificate CA names sent --- SSL handshake has read 0 bytes and written 289 bytes --- Our root certificate appears to be valid, and so far production APNS doesn't appear to be affected, as we're still seeing those push notifications sent successfully. Has anyone else encountered this? I'm wondering if this is a problem on our end or some issue with the APNS Sandbox service?