Error when push notification by postman but not wh

问题:

I send a notification to my android app, to a certain device. When i do it from the Firebase Console I don't get any exception but when I try to post the notification from Postman i get this on the android Log (the notification is received perfectly and the app doesn't stop, it's just a log exception/warning).

W/FirebaseMessaging: Error while parsing timestamp in GCM event
    java.lang.NumberFormatException: s == null
        at java.lang.Integer.parseInt(Integer.java:570)
        at java.lang.Integer.valueOf(Integer.java:794)
        at com.google.firebase.messaging.zzd.zzb(Unknown Source:62)
        at com.google.firebase.messaging.zzd.zzi(Unknown Source:2)
        at com.google.firebase.messaging.FirebaseMessagingService.handleIntent(Unknown Source:365)
        at com.google.firebase.iid.zzg.run(Unknown Source:26)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
        at java.lang.Thread.run(Thread.java:764)

The problem is NOT in the onMessagereceived method.

My post json is just the default one:

{
  "message":{
    "token" : "cBtsRkkSkmY:APA91bGksorrythisisnottherealtokenSn8bavHz8NLxULB1A9CMGrHIyTDU_o7ifHo666pojgur5WVdjH_a_yLV8QQplDL22FPu8çQXyT_TWRYD13mKpTi-N8cs0oVQ9zUXS",
    "notification" : {
      "body" : "Testing",
      "title" : "testiinggg"
      }
   }
 }

It is true, there is no timestamp. I can guess that the Firebase Console does the same but with a timestamp.

My problem is similar to this one but no solution was found for him because of not enough information.

Thank you in advance.