Error in socket.io connection - 'Session ID unknown' - node.js

Question

I have an "Elastic Beanstalk" environment with the scalable server running 2 Ec2 instances.
On my root, I am serving angular 7 content using PHP API (using Codeigniter from API folder). I have socket.io chat module in my Node folder.
I am using Nginx to set up the Node and PHP project in a single EB environment.
I tried different options by modifying my Nginx .conf file as per some research but not able to fix the issue.
Here my Nginx .CONF setting file for SOCKET.IO.
server {
listen 80;
server_name sub.domain.com;
root /var/app/current/node;
location / {
proxy_pass http://127.0.0.1:3000;
proxy_read_timeout 3600;
proxy_connect_timeout 3600;
proxy_redirect off;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header X-Forwarded-Port 443;
proxy_set_header Host $host;
}
}
My socket.io code.
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var port = 3000;
var socketController = require('./socketController.js')
app.get('/', function (req, res) {
res.sendFile(__dirname + '/index.html');
});
var nsp = io.of('/namespace');
/**
* Socket for chat message
*/
io.on('connection', function (socket) {
socket.on('client_user_join', socketController.userJoin.bind(null, socket, nsp, io));
socket.on('client_send_chat_message', socketController.sendChatMessage.bind(null, socket, nsp, io));
socket.on('client_received_chat_message', socketController.receivedChatMessage.bind(null, socket, nsp, io));
socket.on('disconnect', socketController.disconnect.bind(null, socket));
});
http.listen(port, function () {
console.log('listening on *:' + port);
});
I am getting Session ID unknown at intial lever and after few minutes I am getting failed: Error during WebSocket handshake: Unexpected response code: 400
My socket connection link
https://sub.domain.com/socket.io/?EIO=3&transport=polling&t=Mtzwcpj&sid=TSMAaNI0KxDuzcIEAA4s
I already try following option.
Try to connect socket server using different transports.
this.socket = io('https://sub.domain.com/namespace', {transports: ['websocket']});
At the AWS side, enable Stickiness to 1 day.
I do not understand whether it blocking by Nginx configuration or I have to use Radis to fix this as I have two EC2 instances running.