Socket.io + node.js + express + ssl + Nginx - client will not connect - 400 (Bad Request)

Question

I have an express app on a single server running behind nginx I've tested socket.io communication and it runs fine on our dev server. Adding ssl to the mix yielded the following console log on the client: As you can notice it produces a 400 (Bad Request) - and then loads the same request successfully, but my console logs are not being run since the connection is not successful... Would appreciate any feedback. Thanks. This is the code:

This is my nginx config:

upstream example.com {
  server 127.0.0.1:3000;
}

server {
        listen 443 ssl;    
        server_name example.com;

        ssl_certificate       /path/to/nginx/ssl/example.crt;
        ssl_certificate_key   /path/to/nginx/ssl/example.key;

        location / {    
            proxy_pass  http://example.com;
            proxy_redirect off;

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

            proxy_set_header Host $host ;
            proxy_set_header X-Real-IP $remote_addr ;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for ;
            proxy_set_header X-Forwarded-Proto https;      
        }    
        location /public {
            root /var/www/example/;
        }
        location /favicon.ico {
            root /var/www/example/public/favicon.ico;
        }
}
server {
    listen 443 ssl;
    server_name www.example.com;
    return 301 https://example.com$request_uri;
}
server {
    listen 80;
    server_name example.com;
    return 301 https://example.com$request_uri;
}
server {
    listen 80;
    server_name www.example.com;
    return 301 https://example.com$request_uri;
}

this is my socket.io related code on the express server

var express = require('express');
var app = express();
var http = require('http').Server(app);
var io = require('socket.io')(http);

http.listen(port, function(){
    console.log('MyDomain.com app listening at ', 'http://localhost:'+port);

    io.on('connection', function(socket){
        console.log('socket.io connected','socket.id: '+socket.id);

        socket.on('new-user', function(data) {
            var user_id = data.user_id;
            console.log('new-user, user_id: ', user_id);
        });
    });
});

this is my client side that tries to connect:

var socket = io.connect(null, { secure: true, port: 443, rememberTransport: false, 'reopen delay': 1000 });

//I have also tried these variations...
//-----------------------------------------
//var socket = io();
//var socket = io.connect('https://localhost', {secure: true});
//var socket = io.connect('https://example.com',{secure: true});
//var socket = io.connect('https://example.com');
//-----------------------------------------

socket.on('connect', function () { 
    console.log('on "connect"');
    socket.emit('new-user', {user_id:some_user_id});
});

on my html template I'm using this to load socket.io

<script src="/socket.io/socket.io.js"></script>

UPDATE 01: I've noticed that when I go to a different URL in the browser, then come back - the sockets are loading correctly... Does this indicate a delay which is needed...?