Firebase FCM silent push notifications for iOS

Question

I have a problem with silent notifications on iOS.

When my application is in background, I don't receive silent notification sent by FCM. But if I try to send directly to APNS, the notification is successfully received.

This is the JSON sent to FCM:

{ 
"to" : "<token>",
"priority": "high",
"content_available": true,
"data" : {
  "<key>" : "<string>",
  "<key2>" : "<string>"
}

}

This is the JSON sent directly to APNS:

{
  "aps": {
    "content-available": 1
  },
  "<key>": "<string>",
  "<key>": "<string>"
}

I have already tried to remove the "priority" key because I saw someone saying that I shouldn't set the priority if the "content_available" is already set. It didn't work.

1. I have "Push Notifications" enabled in XCode > Capabilities.
2. I have "Remote notifications" checked in Background Modes in XCode > Capabilities.
3. The FCM notifications are working fine when app is in foreground and sometimes when the app is in background.

Answer 1

Waitting for answers