Sending notifications directly using FCM

Please provide the following:

  1. SDK Version: 37
  2. Platforms(Android/iOS/web/all): android

I have a weird issue that I cannot wrap my head around. Hopefully someone can help!

I have setup FCM and expo but I do not want to use expo notification services as I have a complex flow using segment / vero. What I am doing is get the FCM address using:

Notifications.getDevicePushTokenAsync

Then using it to send notifications using Twilio.

Token is correct, how do I know this? Becase if I take that token and I paste it directly in the google cloud messaging Compose notification -> “send test message” dashboard, the notification is received instantly by the device (with the correct app name).

Now… when I use another service (I tried both Twilio and SNS) notifications never arrive. For context, this flow works flawlessly on iOS, the problem is on Android only, no error is returned in Twilio / SNS. Notification is marked as sent correctly.

Is there something I should do app side? I am already doing this at boot:

 if (Platform.OS === 'android') {
      Notifications.createChannelAndroidAsync('default', {
        name: 'default',
        sound: true,
        priority: 'max',
        vibrate: [0, 250, 250, 250],
      });
    }

Is there anything else I might be missing? Is sending the notification directly from the Cloud messaging dashboard different than doing it “traditionally”? Maybe it takes highest precedence?

Any help is greatly appreciated, banging my head on this one for weeks now, am out of ideas…

Tried using expo push token and it works! I am really puzzled by this one, anyone has any idea?

Is the source code for the expo push delivery published anywhere?