Notification Hub and GCM Notifications

I have a Notification Hub and is able to send notifications to Windows and IOS. The problem is when sending to Google devices.

The registration is fine (no error); but when trying to send Notification, it says "The Token obtained from the Token Provider is wrong".

From Service Bus Explorer:

<13:34:27> Notification sent to [myhub] notification hub. State=[DetailedStateAvailable] Success=[0] Failure=[1] TrackingId=[1dea1704-3038-4bbe-8a9d-40e810aa6d6a].

           Results:

             - RegistrationId=[2862313366836604598-8206376917533325615-3] PnsHandle=[APA91bGBMy3TTZ22CprGY5CDt0H3yBJGo3w__BeWVZqQ2jikq-9VppcpybWP1y4z92j9S6hpZAYo5adzEoDtSbbt2OZBe0UvYDCtP_QL-vzyW5M5Bb3FxIXnUsWtwxmQsHyhRap861Ij-WEIzHgbcZ1UeaJz2ZpBKA] ApplicationPlatform=[gcm] Outcome=[The Token obtained from the Token Provider is wrong]

           Body:

           {"data":{"message":"Notification Hub test notification"}}

           Headers:

            - Name=[ServiceBusNotification-Format] Value=[gcm]

The error is not all informative, any ideas what can be wrong ? or what is the best way to debug this issue ?