ESP8266.ping does not work as expected

running on ESP8266-12E
mem:{"free":1557,"usage":143,"total":1700,"history":22}
version:1v85.MaBe_master_d1aeb8f
git_commit:d1aeb8f9f8f692e1c987597624137b546173c08d

tested with .1 (router) and .52 (mac book) - so this works fine for my configuration

>var ESP8266=require("ESP8266");
=function () { [native code] }
>
=undefined
>var Wifi = require("Wifi")
=function () { [native code] }
>Wifi.getIP();
={
  "ip": "192.168.194.64",
  "netmask": "255.255.255.0",
  "gw": "192.168.194.1",
  "mac": "5c:cf:7f:05:c1:00"
 }
>
=undefined
>ESP8266.setLog(2);
=undefined
>ESP8266.ping("192.168.194.1", function(e){ console.log(e);});
=undefined
>456182> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 6,
  "seqNo": 56, "timeoutCount": 0, "bytes": 32, "error": 0 }
>457274> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 57, "timeoutCount": 0, "bytes": 32, "error": 0 }
>458425> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 58, "timeoutCount": 0, "bytes": 32, "error": 0 }
>459499> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 59, "timeoutCount": 0, "bytes": 32, "error": 0 }
>460602> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 4,
  "seqNo": 60, "timeoutCount": 0, "bytes": 32, "error": 0 }
>461723> ping 5, timeout 0, total payload 160 bytes, 5547 ms

ESP8266.ping("192.168.194.52", function(e){ console.log(e);});
=undefined
>750842> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 2,
  "seqNo": 61, "timeoutCount": 0, "bytes": 32, "error": 0 }
>751924> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 62, "timeoutCount": 0, "bytes": 32, "error": 0 }
>753100> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 63, "timeoutCount": 0, "bytes": 32, "error": 0 }
>754175> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 1,
  "seqNo": 64, "timeoutCount": 0, "bytes": 32, "error": 0 }
>755300> Received a ping response!
{ "totalCount": 0, "totalBytes": 0, "totalTime": 0, "respTime": 2,
  "seqNo": 65, "timeoutCount": 0, "bytes": 32, "error": 0 }
>756423> ping 5, timeout 0, total payload 160 bytes, 5582 ms