nginx shows default page when I include www in URL

I have a wordpress site on my CENTOS7 server running NGINX with LEMP. I have created a .conf file and put it in etc/nginx/conf.d, as follows: screenshot of conf file

as you can see, I have included both URL (with and without www) for both my domains in server_name, seperated by space. Now when I try to access sites with www included in the URL, the server returns nginx default page. I've looked for the answer to no avail. what have I done wrong?