phantomjs XHR response code is null - phantomjs

Question

I am using the below code to automate a web page. The web page has an XHR call which is triggered upon submitting the form. By using "onResourceRequest" and "onResponseReceived" I can look into the request body, but the response status code is always null.
PhantomJS version: 2.1.1
var page = require('webpage').create(), testindex = 0, loadInProgress = false;
var config = require('../../config/config.json');
var system = require('system');
console.log('Running Iteration 1 ...');
function waitFor(testFx, onReady, timeOutMillis) {
var maxtimeOutMillis = timeOutMillis ? timeOutMillis : 3000, //< Default Max Timout is 3s
start = new Date().getTime(),
condition = false,
interval = setInterval(function() {
if ( (new Date().getTime() - start < maxtimeOutMillis) && !condition ) {
// If not time-out yet and condition not yet fulfilled
condition = (typeof(testFx) === "string" ? eval(testFx) : testFx()); //< defensive code
} else {
if(!condition) {
// If condition still not fulfilled (timeout but condition is 'false')
console.log("'waitFor()' timeout");
phantom.exit(1);
} else {
// Condition fulfilled (timeout and/or condition is 'true')
console.log("'waitFor()' finished in " + (new Date().getTime() - start) + "ms.");
typeof(onReady) === "string" ? eval(onReady) : onReady(); //< Do what it's supposed to do once the condition is fulfilled
clearInterval(interval); //< Stop this interval
}
}
}, 250); //< repeat check every 250ms
};
page.onError = function (msg, trace) {
console.log(msg);
trace.forEach(function(item) {
console.log(' ', item.file, ':', item.line);
});
};
page.onConsoleMessage = function(msg, lineNum, sourceId) {
console.log(colors.cyan('CONSOLE: ' + msg + ' (from line #' + lineNum + ' in "' + sourceId + '")'));
};
page.onLoadStarted = function() {
loadInProgress = true;
console.log("load started ", page.url);
};
page.onResourceRequested = function(request) {
console.log('Request ' + request.url);
console.log('Request Header :', JSON.stringify(request.headers));
console.log('Request Body :', request.postData);
};
page.onResourceReceived = function(response) {
console.log('Receive ' + response.url, response.status);
if(response.status === null) {
console.log(JSON.stringify(response));
}
};
page.onLoadFinished = function() {
loadInProgress = false;
console.log("load finished ", page.url);
};
var steps = [
function () {
page.open(config.url, function (status) {
if (status !== 'success'){
console.log('Unable to access ', config.url); //This is a HTTPS endpoint
} else {
waitFor(function() {
// Check in the page if a specific element is now visible
return page.evaluate(function() {
return document.getElementById('code').value;
});
}, function() {
console.log("The page dialog should be visible now.");
// phantom.exit();
});
}
});
},
function () {
var isPostMessageSupported = page.evaluate(function() {
if(window.postMessage){
return true;
} else{
return false;
}
});
console.log('POST Message Support : ', isPostMessageSupported);
var guid = page.evaluate(function() {
return document.getElementById('guid').value;
});
console.log('GUID : ', guid);
page.evaluate( function () {
document.getElementById('userid').value = 'myusername';
document.getElementById('pass').value = 'mypassword';
});
},
function () {
page.evaluate(function () {
document.getElementById('myform').submit();
return;
});
},
function () {
page.render('iteration1.png');
},
];
function done(){
console.log('##completed');
}
setInterval(function() {
if (!loadInProgress && typeof steps[testindex] == "function") {
console.log("step " + (testindex + 1));
steps[testindex]();
testindex++;
}
if (typeof steps[testindex] != "function") {
console.log("test complete!");
done();
phantom.exit();
}
}, 50);
The response that I recieve for the XHR call is
{"contentType":null,"headers":[],"id":42,"redirectURL":null,"stage":"end","status":null,"statusText":null,"time":"2018-04-12T04:15:04.402Z","url":"https://example.com/p"}
I have tried all the phantomJS command line arguments
phantomjs --web-security=false --ssl-protocol=tlsv1 --ignore-ssl-errors=true phantomjs/iterations/iteration1.js
I have also tried adding header "Connection:keep-alive". But nothing solves my problem.
I am not sure what could be the problem here.