ssl have problem with application/x-www-form-urlencoded content type

Question

We used nginx to configure our node js project. Everything works fine until we add ssl. After that, it blocks POST requests with "application/x-www-form-urlencoded" content-type and rewrites it to GET.

My config:

server {
    listen 80;
    listen [::]:80;
    server_name domain.online www.domain.online;

    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl;
    server_name domain.online www.domain.online;

    # SSL certificate paths
    ssl_certificate /etc/ssl/private/letsencrypt-domain.pem;
    ssl_certificate_key /etc/ssl/private/letsencrypt-domain.key;

    # SSL configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers 'TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384';

    # Enable OCSP stapling
    ssl_stapling on;
    ssl_stapling_verify on;

    # Set the path to your certificate's CA bundle
    #ssl_trusted_certificate /path/to/your/CA_bundle.pem;

    # Enable HSTS (optional but recommended)
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    location / {
        proxy_pass http://127.0.0.1:8080;  # Adjust this to your backend app's address and port
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Frame-Options SAMEORIGIN;
        proxy_set_header X-Content-Type-Options nosniff;
        proxy_set_header X-XSS-Protection "1; mode=block";
    }
}

I removed the ssl certificate and replaced it with a new one but it didn't work.