ESP8266 server only serves page once, sometimes twice

Hi!
I'm facing with the same issue. Only the first http request served.
I'm using an ESP8266 with this firmware version:

>Serial2.setup(115200,{
:  rx:A3,
:  tx:A2,
:  bytesize:8,
:  parity:'none',
:  stopbits:1,
:  flow:'none'});
=undefined
>Serial2.on('data',function(d) { console.log(d); });
=undefined
>Serial2.write("AT+GMR\r\n");
=undefined
AT+GMR
AT version:0.21.0.0
SDK version:0.9
.5
OK

I also have insalled a temperature and air pressure sensor, which I wanted to serve as json data.
But it arrives like this:

AT+CIPSEND=0,47
xt

{"pressure":100727,"temperature":27.8375}

This is the code I used (Almost identical to the ESP8266's sample code)

Serial2.setup(115200,{
  rx:A3,
  tx:A2,
  bytesize:8,
  parity:'none',
  stopbits:1,
  flow:'none'});
status = "Connecting to ESP8266";
var wifi = require("ESP8266WiFi").connect(Serial2, function(err) {
  if (err) throw err;
  status = "Reseting wifi module";
  wifi.reset(function(err) {
    if (err) throw err;
    status = "Connecting to " + SSID;
    wifi.connect(SSID,code, function(err) {
      if (err) {status = err; throw err;}
      wifi.getIP(function(err, ip){
        status = err || ("IP: " + ip);
      });
      var http = require("http").createServer(onPageRequest);
      http.listen(80);
      status = "HTTP server started";
      });
    });
  });
function onPageRequest(req, res){
  res.writeHead(200, {'Content-Type': 'content/text'});
  res.end(JSON.stringify(lastValue));
  status = "Request served";
}

What is the advised firmware to use on ESP8266?
Also I'm using an Espruino Pico with 1v79 firmware.

(Excuse my English, I'm not a native speaker.)