ESP8266.ping does not work as expected

Hi All,
I'm simply trying to send a ping request to my router with ESP8266.ping function, my callback gets called but the result is always negative as if my router is not alive but it is. I have the latest nodeMCU board with espruino 1v85. Any idea?

The code I'm running :

var ESP8266=require("ESP8266");

ESP8266.ping("192.168.1.1", function(e){

  console.log(e);

});

and the result :

{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 0, 
  "seqNo": 0, "timeoutCount": 0, "bytes": 0, "error": -1 }