FirebaseMessaging.TokenReceived never gets triggered

For some reason the methode TokenReceived never gets called on my Android device. The script looks like this:

public class FCM : MonoBehaviour
{
    public TextMeshProUGUI text;
    // Start is called before the first frame update
    void Start()
    {
        Firebase.Messaging.FirebaseMessaging.TokenReceived += TokenReceived;
        Firebase.Messaging.FirebaseMessaging.MessageReceived += MessageReceived;
   
    }

    public void MessageReceived(object sender, MessageReceivedEventArgs e)
    {
        Debug.Log("Message received: " + e.Message);
    }

    public void TokenReceived(object sender, TokenReceivedEventArgs e)
    {
        Debug.Log("Token received: "+ e.Token);
        text.text = "received a token";
    }
}

I made sure that i have the latest Firebase SDK and i am also able to send a push notification to every device(via firebase console). Now i wanna have the methode TokenReceived triggered, so i can safe that token in my database. I also followed all the steps from: https://firebase.google.com/docs/cloud-messaging/unity/client. Is there anything i am missing?