Firebase – .NET MAUI – Why would push notifications not work the same after publishing?

So I have a .NET MAUI mobile application targeting Android specifically that has implemented push notifications through the OnMessageReceived() method and OnNewToken() using an intent filter and service.

In development when I run the application on a connected device it all works perfectly and OnMessageReceived() is received as expected.

However, when publishing it to an APK file instead of OnMessageReceived() being called, a local notification is displayed, even in the foreground. I have no code that enables this feature.

Not sure if this is a .NET MAUI specific issue or something to do with firebase.
My code for receiving notifications is:

[Service(Exported = false)]
[IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]
public class PushNotificationFirebaseMessagingService : FirebaseMessagingService
{
    /// <summary>
    /// Called when a new token is created
    /// </summary>
    /// <param name="token">The token created</param>
    public override void OnNewToken(string token)
    {
        try
        {
            // Set the token name to secure storage
            SecureStorage.SetAsync(Constants.PushNotificationTokenName, token)
                         .SafeFireAndForget(false);
        }
        catch (Exception)
        {
            // Could be secure storage is not supported
        }


    }

    /// <summary>
    /// Called when any new notification hub message is received
    /// </summary>
    /// <param name="message">The message received</param>
    public override void OnMessageReceived(RemoteMessage message)
    {
       // Code executed on UI here
                

}

    }



}

And my MainActivity.cs code…

    protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.PostNotifications) != Permission.Granted)
    {
        ActivityCompat.RequestPermissions(this, new[] { Manifest.Permission.PostNotifications }, 0);
    }
    CreateNotificationChannelIfNeeded();


}


private void CreateNotificationChannelIfNeeded()
{
    if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
    {
        CreateNotificationChannel();
    }
}

private void CreateNotificationChannel()
{
    var channelId = $"{PackageName}.general";
    var notificationManager = (NotificationManager)GetSystemService(NotificationService);
    var channel = new NotificationChannel(channelId, "General", NotificationImportance.Default);
    notificationManager.CreateNotificationChannel(channel);
    FirebaseCloudMessagingImplementation.ChannelId = channelId;
    //FirebaseCloudMessagingImplementation.SmallIconRef = Resource.Drawable.ic_push_small;
}

Things to note:

• I have the permission <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/> in my AndroidManifest.xml