Notifications not received | Apple Developer Forums

I am trying to configure a Parse server & iOS app combination with push notifications. The Parse server is a docker container, currently run as a Docker container on a private network behind a reverse proxy, i.e. each container does not have any external inbound traffic allowed unless defined, but is able outbound. I am testing the iOS app also running on my local network initially.

I have followed various guides at:

Ray Wenderlich and another about Parse
Appcoda
Parse’s own Guides, right down to the section on adding my device to Parse with PFInstallation

I have the CSR file, the downloaded `.cer` file from the Apple Developer portal and the exported `p.12` from the installed certificate.From this configuration, I have run the iOS app a couple times on my iOS 13.4 iPhone, so it has asked for push notification permission and completed the registration / installation of the device into Parse. This is listed as an "installation" as Parse refers to it.Using their separate Dashboard UI, I attempt to send a notification to the "everyone" audience, i.e. all registered devices. But it is never received on the device. I downloaded the APNS-Tool app from the Mac App Store and from there, using the same certificates and private keys, I sent notification, that appeared as though from my iOS demo app on the same device, so I know the certificates are in order.Following the Parse guide, a notification can be simulated with, which I have run on the Parse container terminal:

curl -X POST \
  -H "X-Parse-Application-Id: you_app_id" \
  -H "X-Parse-Master-Key: your_master_key" \
  -H "Content-Type: application/json" \
  -d '{
  "where": {
  "deviceType": {
  "$in": [
  "ios",
  "android"
  ]
  }
  },
  "data": {
  "title": "The Shining",
  "alert": "All work and no play makes Jack a dull boy."
  }
  }'\ http://your_server_address:1337/parse/push

My Docker container uses a different port number, but above is the default. For me, this returns:{"result":true}I have also applied the additional data fields, following guidance from Parse documentation:

"push-type" / "push_type" / "apns-push-type" = "background"
"content-available": 1

The notification is not received on the device, but is viewable in the Past Pushes section of the Dashboard UI. This would seem to be functioning as expected with message sent up successfully to Apple's APNS servers. I don't know what else to try.

Can anyone provide assistance?