nodejs app is getting 404 on REST api nodejs app hosted in localhost

I have a nodejs REST api hosted on localhost and I have a nodejs app that is consuming it. This app too is running on localhost. Everything was working fine but after a restart the webapp just could not connect to the REST api anymore. I am running Windows 10.

I tested the REST api with postman and also with browser, it worked. There is no issue with the REST api.

Tried changing the port numbers - same result.

I ran wireshark to see the difference between when requesting from browser and from nodejs webapp. Below is the screenshot. First two lines are when the nodejs app made the request and the next two are from browser.

I am not able to understand what is wrong here. I tried with a standalone nodejs script, that too failed. Below is the script I used.

var request = require('request');
var u = "xxx";
var p = "xxx";
var auth = "Basic " + new Buffer(u + ":" + p).toString("base64");
var username = "qqqq";
var password = "eeee";



var options = {

            url : 'http://localhost:4001/api/v1/transaction',
            headers : {
                "Authorization" : auth
            },
        };   

        console.log(options.url);

        request.get(options, function(error,response,body){
            //console.log(options);
            //console.log(response);
            console.log(response.statusCode);
            console.log(body);
            if (!error && response.statusCode == 200) {
                var userObj = JSON.parse(body);
                callback(userObj);
            } else {
                console.log("---- Error ----")
                console.log(error);             
            }
        });

via unlimit