Tableau Server 2020.3 with NGINX Reverse Proxy Set up, return error : ERR_EMPTY_RESPONSE when accessed from external network.

Hi, I have set up Tableau server version 2020.3 (deployed in Windows Server 2012 R2) behind NGINX reverse proxy. I also have registered domain for our Tableau server. However, when I access the URL (let say : tableau.mydomain.com) i got "ERR_EMPTY_RESPONSE".

I share my NGINX configuration for Tableau Server :

# Tableau Server
 
upstream tableau {
        server 10.22.177.57;  # Tableau Server IP Address
}
 
###############################
# Reverse Proxy Configuration #
###############################
 
server {
        listen          80;
        server_name     tableau.mydomain.com; # Let say this is my tableau registered domain
 
        location / {
                proxy_pass      http://tableau;
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header REMOTE_ADDR $remote_addr;
                proxy_set_header X-Forwarded-Host $host;
                proxy_set_header X-Forwarded-Server $host;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto http;
                proxy_connect_timeout 60;
                proxy_read_timeout 60;
                proxy_send_timeout 60;
                send_timeout 60;
                proxy_http_version 1.1;
                proxy_set_header Connection "";
                proxy_set_header Referer $http_referer;
        }
}

I try set up without SSL / TLS first to try it if this set up work not while to get my SSL / TLS certificate, Unfortunately its not working.

I also configured the Tableau Server with using command below :

tsm configuration set -k gateway.trusted -v "103.157.82.80, 103.157.82.81"  # 1st and 2nd load balancer public IP
 
tsm configuration set -k gateway.public.host -v "tableau.mydomain.com"
tsm configuration set -k gateway.trusted_hosts -v "tableau.mydomain.com"
tsm configuration set -k gateway.public.port -v "80"
tsm pending-changes apply

Accessing tableau server internally no issue so far and I also checked firewall to make sure its not blocking port 80 from outside network. I still not what cause this issue, I have check this site "https://kb.tableau.com/articles/issue/error-this-page-isn-t-working-ip-address-didn-t-send-any-data-err-empty-response-when-configuring-reverse-proxy" also not work.

I`ll really appreciate if someone have workaround for this issue. Thank you.