Socket.io events are not triggering on live ubuntu server

Question

I have used socket.io for live updates inside nodejs application. As When I integrated it on localhost it is working fine. I am getting all the events.

But as soon as I am deploying it to production server, my socket is not connecting and not even calling any events. I have deployed node js application on ubuntu server. And I have used nginx for reverse proxy. We have also integrated ssl into our domain.

This is my app.js

const express = require('express');
const cors = require('cors');

const app = express();

app.use(cors());

app.use('/api', rootRouter);

//socket setup
var http = require('http').createServer(app);
var io = require('socket.io')(http);

io.on('connection', (socket) => {
    console.log('we have new connection');

    socket.on('initiateConnection', async data => {

        const { userId } = data;
        socket.userId = userId;
        socket.join(userId);
        io.sockets.in(userId).emit('InitiatedConnection', userId);

        console.log('User connected with id - ', data.userId);
    });

    socket.on("disconnect", async (reason) => {
        if (socket.userId) {

            const userId = socket.userId;
            socket.leave(socket.userId);
            console.log("user disconnected with id - " + userId);
        }
    });

    socket.on('newOrderCreated', async data => {
        console.log('newOrderCreated called', data)
        io.sockets.in(data.userId).emit('OrderReceived', data);
    })
});

const port = process.env.PORT || 3000;

http.listen(port, function () {
    console.log(`listening on *:${port}`);
});

module.exports = app;

And For testing purpose I was trying to call socket from one of router file. That is I have initialised one client from my orders controller. Code for same is as follows

/controllers/ordersController.js

const io = require('socket.io-client');
//const SOCKET_ENDPOINT = 'http://localhost:3000/' // endpoint for localhost
const SOCKET_ENDPOINT = 'https://example.com/' // endpoint for live server
const socket = io(`${SOCKET_ENDPOINT}`);

socket.on('OrderReceived', (data) => {
    console.log('New Request order received', data);
})

module.exports = {
    findNearbyOutlet: async(req, res) => {

        console.log('socket', socket)
        let userId = req?.loggedInUserId ? req?.loggedInUserId : 0;

        //emit this event to initiate connection with server
        socket.emit('initiateConnection', {
            userId
        });

        //emit this event to broadcast message about new order
        socket.emit('newOrderCreated', {
            orderId: 1,
            userId: userId,
            orderDate: '2022-05-02',
            userName: 'Some user',
            address: 'Atos society, C/1102, Jaipur, India-411110'
            totalAmount: 100
        })
    }
}

For your information We have integrated SSL with our domain. Following is the nginx configuration for our site

server {
  listen 443 ssl;
  ssl_certificate /var/www/ssl/example.com/bundle.crt;
  ssl_certificate_key /var/www/ssl/example.com/HSSL-6256604eeb4e6.key;
  server_name example.com www.example.com;
  location / {
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $host;

      proxy_pass http://localhost:3000;

      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection 'upgrade';

      proxy_cache_bypass $http_upgrade;
      client_max_body_size 100M;
  }
}

server {
 listen 80;
 server_name example.com www.example.com;
 return 301 https://$server_name$request_uri;
}

So I have did this much for deployment purpose. Rest of everything is working fine. Only thing is socket.io events are not triggering. Event socket connection is not working. Everything working fine on localhost but not on live server.

I have tried lot of stuff but no clue why socket events are not working. Please help me in this socket setup on live server. Let me know what am I missing.

Thanks in advance.