nginx directing domain to wrong site

Question

I have a server running nginx for a couple WordPress sites. My existing sites work fine but I'm trying to add another site right now and the new domain I'm setting up is redirecting to another site. I don't have a default host it's going to the domain that's alphabetically first on the server which my understanding is nginx behaviour when it doesn't have a match for the domain coming in.

So here's my config for the new domain:

server {
    listen 80;
    server_name domain.com.au www.domain.com.au;
    root /var/www/domain.com.au/html;
    index index.php index.html;
    location / {
        try_files $uri $uri/ /index.php?args;
    }
    location ~\.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.2-fpm.sock;
    }
}