Debugging Django on a deployed remote server

Question

I am running Django with Nginx and Gunicorn on a remote server. There are certain types of interactions I can do on the remote machine (via my web browser) that will cause the webserver to respond with a "502 Bad Gateway nginx/1.10.3 (Ubuntu)" error after doing certain POST operations to the Django webserver. This error happens repeatably after exactly 30 seconds. Which makes me think it's some kind of timeout with Nginx.

When I run the Django server locally everything runs fine. But I don't think this is a problem with Nginx, I think it's a problem with Django on the remote system.

Can anybody provide any guidance about how to see what is going on with Django on the remote machine? Or how to debug this problem further.

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        ##
        #Time Out Settings
        ##

        proxy_read_timeout 300;
        proxy_connect_timeout 300;
        proxy_send_timeout 300;
        send_timeout 300;

        ##
        # Gzip Settings
        ##

        gzip on;
        gzip_disable "msie6";

        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss tex$

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}


#mail {
#       # See sample authentication script at:
#       # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
#       # auth_http localhost/auth.php;
#       # pop3_capabilities "TOP" "USER";
#       # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
#       server {
#               listen     localhost:110;
#               protocol   pop3;
#               proxy      on;
#       }
#}

contents of /etc/nginx/sites-enabled: I have replaced my IP address with xxx.xxx.xxx.xxx and server name with "myservername"

server {
    server_name xxx.xxx.xxx.xxx backend.myservername.com www.backend.myservername.com;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
        root /home/django/my_django_project;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/home/django/my_django_project/django_subfolder/django_subfolder.sock;
    }

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


    listen 80;
    server_name xxx.xxx.xxx.xxx backend.myservername.com www.backend.myservername.com;
    return 404; # managed by Certbot


}'''