I'm having trouble moving a wordpress website to a new LEMP server. lets use "example.com" as the example. I successfully copied the PHP files and the database to the new server and temporarily set it up as "example.org" so the "live" example.com would keep functioning while I worked on the new server. I created a server block for it and example.org was working just fine.
Here is the partial server block code that was working with the .ORG site.

server {
    listen 80;
    listen [::]:80;

    root /var/www/example.com/html;
    index index.php index.html index.htm;

    server_name example.org www.example.org;

   location / {
        try_files $uri $uri/ /index.php?q=$uri&$args;
    }
}

PLEASE NOTE: We already had a very busy production web site on the LEMP server at "email.example.com", a sub-domain we use for our email campaigns. That site has been working very well for 6 months. It was using the DEFAULT server block and still is. Here is the code for that site.

# Default server configuration
#
server {
                listen 80 default_server;
                listen [::]:80 default_server;

        root /var/www/html;

                # Add index.php to the list if you are using PHP
                index index.php index.html index.htm index.nginx-debian.html;

                server_name email.example.com mailer.example.com;

                try_files $uri $uri/ =404;
                }
}

Since everything was working great with "email.example.com" the default site, and "example.org" the new site, I decided to point "example.com" to the IP address of the new LEMP server. I edited the Server block for the new site to reflect the server names "example.com www.example.com" as below. I included some redirects, which I hope are correct, so that "example.org" and "example.net" also, hopefully, resolve to "example.com".

server {
    listen 80;
    listen [::]:80;

    root /var/www/example.com/html;
    index index.php index.html index.htm;

    server_name example.com www.example.com;

                rewrite ^/(.*)$ http://example.org/$1 permanent;
    rewrite ^/(.*)$ http://example.net/$1 permanent;

                location / {
        try_files $uri $uri/ /index.php?q=$uri&$args;
    }
}

And YES I also changed the entries in the wp_options wordpress table for "siteurl" and "home" to "http://example.com".

BUT now when I enter example.com or example.org or example.net into my browser the DEFAULT website *http://email.example.com * appears instead of the new site! But the URL displayed in the Browser is example.com. Right URL but Wrong website.

Please help if anyone can tell me what I may have done wrong.