wss handshake error 200 when connecting to flask socketio

Question

I have a flask server and an angularjs front end. I am trying to create a websocket that makes 3rd party API calls and spits out the results in an async fashion (using celery).

The current implementation works perfectly on my localhost dev environment. However, when I push it to my server, I get the following error:

WebSocket connection to 'wss://' failed: Error during WebSocket handshake: Unexpected response code: 200

I have given below the relevant codes for my front end, server and and nginx confguration files:

front end controller:

quotesocket = io.connect(myurl.url2,{'force new connection': true,'path':'/api/socket.io'});
quotesocket.on('connect', function(){
        // console.log('socket');
});

... 
and the rest of the code for event based emits go here

My nginx configuration:

sites-available (this is inside the 80 block. I redirect all traffic to https and I use a certbot SSL):

   location /quote1{
           proxy_pass      http://127.0.0.1:5000/quote1;
           proxy_http_version 1.1;
           #proxy_redirect     off;
           proxy_buffering off;
           #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 Upgrade $http_upgrade;
           proxy_set_header Connection "upgrade";
           proxy_read_timeout 86400;

}

nginx.conf:

http {

        ##
        # Basic Settings
        ##

        ##
        # Timeout settings for proxy connections
        ##

        proxy_connect_timeout 150s;
        proxy_read_timeout 150s;

.....
}

My flask server:

@socketio.on('connect', namespace='/quote1')
def test_connect():
    """code for connecting"""

I have defined separate defs for events (connect, disconnect_request, disconnect, my_event, etc)

Can anyone here let me know where im going wrong?

Regards, Galeej