IONIC 5 FCM Plugin onNotification not fired when app is killed/closed (IOS & Android)

I am stuck with a problem in both platforms with FCM plugin (https://ionicframework.com/docs/native/fcm), the problem is I can´t handle notifications when app is closed/killed , the onNotification() method isn´t fired (it works fine in background and foreground)

this.fcm.onNotification().subscribe((payload) => {
          if (payload.wasTapped) {
            console.log('Notification received in background');
          } else {
            console.log('Notification received in foreground');
          }
          console.log('Notification payload: ',payload);
  });

notification body working fine in background and foreground (both platforms):

{
 "to" : <device-key>,
"collapse_key" : "app-key",
 "notification" : {
     "body" : "body",
     "title": "title"
 },
 "data" : {"parameter":"1"},
 "android": {
    "notification": {
      "click_action": "FCM_PLUGIN_ACTIVITY"
    }
  }
}

The ionic info output for IOS environment:

Ionic:

   Ionic CLI                     : 6.11.10 (/usr/local/lib/node_modules/@ionic/cli)
   Ionic Framework               : @ionic/angular 5.3.3
   @angular-devkit/build-angular : 0.901.12
   @angular-devkit/schematics    : 9.1.12
   @angular/cli                  : 9.1.12
   @ionic/angular-toolkit        : 2.3.3

Cordova:

   Cordova CLI       : 10.0.0
   Cordova Platforms : ios 6.1.1
   Cordova Plugins   : cordova-plugin-fcm-with-dependecy-updated: ^7.3.1

System:

   ios-sim : 8.0.2
   NodeJS  : v14.13.0 (/usr/local/Cellar/node/14.13.0/bin/node)
   npm     : 6.14.8
   OS      : macOS Catalina
   Xcode   : Xcode 12.0.1 Build version 12A7300

@alexmigwi made some suggestions in this thread.