NGINX 重定向 http 到 https 不起作用

Question

I was trying to set up a wordpress web server using nginx on my own laptop. The certificate was installed successfully and I can visit my site through https. However, I found out that the redirecting from http to https is not working. My site always showed 400 Bad Request when I tried to visit through http. Lots of answers on Google say that this can be fixed by commenting out "ssl on" but actually I don't have this line in my code.

server {
    root /var/www/html;
    index index.php index.html index.htm;
    server_name mydomain.com;

    location / {
            try_files $uri $uri/ =404;
    }

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

    location ~ /\.ht {
            deny all;
    }

listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/mydomain.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/mydomain.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 ($host = mydomain.com) {
    return 301 https://$host$request_uri;

    } # managed by Certbot


    listen 80 default_server;
    server_name mydomain.com;
    return 404; # managed by Certbot
 }

Answer 1

I found out the problem was coming from my NAT setting. The external 80 and 443 connections were forwarded to my internal server's port 443 under 1 NAT rule. After separating 80 and 443 to different rules and everything works!