http – Nginx showing 504 Gateway timed out when uploading large files

I have a simple PHP file upload script that uploads a file. The server consists of 1 nginx reverse proxy and another nginx server (upstream). The problem is that when I try to upload very large files ~ 2GB then I get an error:

504 Gateway Time-out

Here is my reverse proxy configuration:

server {
    listen 80;
    
    server_name upload.mycloudhost.com;

    proxy_buffer_size 1024k;
    proxy_buffers 4 1024k;
    proxy_busy_buffers_size 1024k;
    proxy_connect_timeout       600;
    proxy_send_timeout          600;
    proxy_read_timeout          600;
    send_timeout                600;
    client_body_timeout         600;
    client_header_timeout       600;
    keepalive_timeout           600;
    uwsgi_read_timeout          600;

    location / {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $host;
        proxy_pass http://localhost:13670;
    }
}

And here is the other nginx server (upstream):

server {
    listen 80;
    
    server_name upload.mycloudhost.com;

    client_max_body_size 80G;
    proxy_buffer_size 1024k;
    proxy_buffers 4 1024k;
    proxy_busy_buffers_size 1024k;
    proxy_connect_timeout       600;
    proxy_send_timeout          600;
    proxy_read_timeout          600;
    send_timeout                600;
    client_body_timeout         600;
    client_header_timeout       600;
    keepalive_timeout           600;
    uwsgi_read_timeout          600;

    root /var/www/mycloudhost;
    index index.php index.html index.htm index.nginx-debian.html;

    location ~ .php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass php:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }

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