I am creating an library meant to be used on other apps and that will receive it's own Firebase message from a separate sender. I got two Firebase token token, one for the app I am using to test the sdk, and the other for the sdk, using different senderID I created
String token_app = FirebaseInstanceId.getInstance().getToken();
String token_sdk = FirebaseInstanceId.getInstance().getToken(<my-sdk-project-id>, FirebaseMessaging.INSTANCE_ID_SCOPE);
On the Firebase Console, I tried to test those token by sending message to them. When I send a message from that app project, using the token_app, I receive notification and data as expected.
However, when I try with my sdk project, with the token_sdk, I do not receive anything. The notification is sent from the console, without error, but the device do not receive anything, with tha app itself either in the foreground or in the background.
Is there something special to do to receive message from multiple sender? The Firebase doc do not go deep into the subject.