Hello, We are investigating an intermittent production VoIP push issue involving Twilio, PushKit, and CallKit. For one incoming call, an iPad registered to the same Twilio identity received the VoIP push and successfully reported the call to CallKit. An iPhone had no corresponding native push-received, call-invite, or CallKit reporting events. The iPhone successfully received, displayed, and answered calls both before and after the affected call. Twilio engineering has confirmed the APNs ID and its association with the affected iPhone device token. We have the exact UTC timestamp, app/device versions, provider correspondence, and a client event timeline. We can provide these through a private channel. There is also a client logging gap around the incident, so we are not treating missing client events as proof of APNs non-delivery. We would like to determine whether APNs received the specific request, attempted delivery, and has any delivery outcome information available. We do not have a focused sample Xcode project that reproduces this historical incident. Selecting No for that question in the code-level support request form directs us to the forums. Could an Apple engineer advise: How can we request a private APNs delivery investigation using the provider-confirmed APNs ID and timestamp? Is there an appropriate support or Feedback Assistant route for a production incident without a reproducible sample project? Which additional provider records or device diagnostics should we collect? We have omitted device tokens, request identifiers, and detailed logs from this public post and can supply them through an appropriate private channel. Thank you.