Running daphne behind nginx reverse proxy with protocol upgrade always routes to http instead of websocket

I am trying to deploy django channels powered notification application behind Nginx reverse proxy server to only serve the websocket communications, while having Nginx + uWSGI setup to serve the django application.

The application works in my local machine seamlessly when run with either python manage.py runserver --noasgi + daphne -p 8000 myproject.asgi:application or python manage.py runserver with daphne handling all the requests internally.

Problem:

All the websocket requests are routed to http protocol type instead of websocket protocol type and it returns WebSocket connection to 'ws://ip_address/ws/' failed: Error during WebSocket handshake: Unexpected response code: 404

Packages Installed:

Django==2.0.3
channels==2.0.2
channels-redis==2.1.1
daphne==2.1.0
asgiref==2.3.0
Twisted==17.9.0
aioredis==1.0.0
autobahn==18.4.1

Environment:

Ubuntu - 16.04
Nginx - 1.12.0

Nginx Configuration for upgrading the request:

map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

# the upstream component nginx needs to connect to websocket requests
upstream websocket {
    server unix:/path/to/my/app/daphne.sock;
}

# configuration of the server
server {

        # the port your site will be served on
        listen      80;

        # the domain name it will serve for
        server_name ip_address;
        charset     utf-8;

       # Sending all non-media requests for websockets to the Daphne server.
        location /ws/ {
            proxy_pass http://websocket;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;
        }

}

routing.py

from django.conf.urls import url

from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
from myapp import consumers

application = ProtocolTypeRouter({
    'websocket': AuthMiddlewareStack(
        URLRouter([
            url(r'^ws/$', consumers.MyConsumer),
        ])
    ),
})

Daphne Logs:

None - - [TimeStamp] "GET /ws/" 404 3
None - - [TimeStamp] "GET /ws/" 404 3
None - - [TimeStamp] "GET /ws/" 404 3

Kindly let me know if anything in addition is required to help.

P.S: I have deployed the same application in two servers(both having the same configuration and environment as above) and the result was same.