Rails 5 application(nginx/puma) with Subdomain is not working even after adding the A Records.

HI, I have recently setup the main domain, for example…domain.com(new droplet) on rails 5 and it got deployed and live successfully. Now I want to use subdomain.domain.com, which is an distinct application(added new droplet) using the same domain name and hence i have also added required entries in the Domain setting as shown below. I have just renamed my subdomain and domain to default names -

in domain.com settings - 2A RECORDS/3NS RECORDS

Hostname                 | Value
-------------            | -------------
subdomain.domain.com     | new_droplet_ip_subdomain
domain.com               | droplet_ip_domain
domain.com               | ns1,ns2,ns3 entires(rented from godaddy) 

also added subdomain.domain.com …settings

(Type)Hostname                   | Value
-------------                    | -------------
(cname)*.subdomain.domain.com    | subdomain.domain.com
(a record)domain.com             | droplet_ip_domain
3 ns records                     | ns1,ns2,ns3 entires(rented from godaddy) 

Moreover there is also a PTR record for -

IPADRESS              |  PTR Record    
-------------------------------------
sub_domain_ip_address | subdomain.domain.

MOrover, there is firewall open to all ports

Type	Protocol	Port Range	Sources	
SSH	TCP	22	All IPv4 All IPv6	More 
HTTP	TCP	80	All IPv4 All IPv6	More 
HTTPS	TCP	443	All IPv4 All IPv6	More 
Custom	TCP	2812	All IPv4 All IPv6	More 

I am not able to understand why its still failing as I cannot see a single log generated in the subdomain_server_ip, where deployment is successful.I am sure, I am making some mistake in the DNS, but what is that.I have also referred DNS details for Digital Ocean but still when I hit subdomain.domain.com on browser, it just keeps loading and stops saying that subdomain.domain.com took too long to respond.

I already have successfully deployed domain.com and its working great. So, 1- do i need to update hosts file?..i did but still the same 2- when I ping - ping subdomain.domain.com, it works and packets are received. 3- NO logs are generated on the subdomain.domain.com server, when I login using ssh user@ip, nginx and puma is working and started, but no logs. 4- On the browser, when I hit subdomain.domain.com, it get subdomain.domain.com took too long to respond.

5- my /etc/nginx/sites-enabled/subdomain.domain.com file looks like shown below: –

  
upstream puma {
  server unix:///home/mike/apps/domain/shared/tmp/sockets/domain-puma.sock;
}

server {
  listen xx.xxx.xx.xxx:80 default deferred;
  server_name www.subdomain.domain.com, subdomain.domain.com;

  root /home/mike/apps/domain/current/public;
  access_log /home/mike/apps/domain/current/log/nginx.access.log;
  error_log /home/mike/apps/domain/current/log/nginx.error.log info;

  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  try_files $uri/index.html $uri @puma;
  location @puma {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;

    proxy_pass http://puma;
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 10M;
  keepalive_timeout 10;
}

Can somebody help or give me some ideas as what is missing.