After implementation of firebase_messaging with the official documentation and adding the configuration functions with this guide : https://medium.com/flutterpub/enabling-firebase-cloud-messaging-push-notifications-with-flutter-39b08f2ed723 .
onMessage, onResume and onLaunch output also only shows, while app is in foreground. If not in foreground, the notification will be returned as soon as the app is again in foreground. Also linked all onMessage, onResume and onLaunch with the local_notifications plugin. As with the Log Output, notifications only appear while app is in foreground.

Has anyone experienced a similar issue or/and can please help me?