Nginx and multiple sites issue on Ubuntu 20.04

I have a droplet for hosting three sites, all of them using Kirby CMS, a PHP based, flat-file CMS.

I followed this tutorial to setup Nginx and PHP: https://www.digitalocean.com/community/tutorials/how-to-install-linux-nginx-mysql-php-lemp-stack-on-ubuntu-20-04

I’ve setup a separate nginx config for each site, like so:

var/www/site1.com
var/www/site2.com
var/www/site3.com

Whenever I go to site1.com, it works as expected. When I go to site2.com, it looks like site 1, but the URL in the browser shows site1.com. If I go to site2.com/index.php I see the proper site that I expected.

Here’s what the site1 nginx config looks like:

server {
    server_name site1.com www.site1.com;
    root /var/www/site1.com;

    index index.php index.html index.htm;

    client_max_body_size 100M;

    # Don't hint these as folders
    rewrite ^/(content|site|kirby)$ /error last;

    # block content
    rewrite ^/content/(.*).(txt|md|mdown)$ /error last;

    # block all files in the site and kirby folder from being accessed directly
    rewrite ^/(site|kirby)/(.*)$ /error last;

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location ~ /panel {
        autoindex off;
        try_files $uri $uri/ /panel/index.php$uri&$args;
    }

    location ~ (?:^|/)\. {
        deny all;
    }

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/var/run/php/php7.4-fpm.sock;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
     }

    location ~ /\.ht {
        deny all;
    }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/site1.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/site1.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot


}
server {
    if ($host = www.site1.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    if ($host = site1.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    listen 80;
    server_name site1.com www.site1.com;
    return 404; # managed by Certbot

}

Site 2’s config looks the same except the URLs are changed and it doesn’t have the Let’s Encrypt stuff yet since I can’t seem to get it to confirm ownership of the domains.