This site can’t be reached bi.gehnios.com took too long to respond. Any idea why this could be happening?

When trying to open the site in the subdomain bi.gehnios.com (running our metabase platform), the page is giving me the message in the title.

I tried clearing the cache, and also review the settings in my default file :

server {

listen                      443 ssl http2;
listen                      [::]:443 ssl http2;

server_name                 bi.gehnios.com;

include                     ssl_params;
ssl_certificate      /etc/letsencrypt/live/bi.gehnios.com/fullchain.pem;
ssl_certificate_key  /etc/letsencrypt/live/bi.gehnios.com/privkey.pem;
ssl_dhparam          /etc/letsencrypt/live/bi.gehnios.com/dhparams.pem;
ssl_trusted_certificate     /etc/letsencrypt/live/bi.gehnios.com/chain.pem;

}

server {

listen                      80;
listen                      [::]:80;

server_name                 bi.gehnios.com;

return                      301 https://bi.gehnios.com$request_uri;

}

I also checked the SSL certificate and it seems it is fine after checking its status…

Found the following certs:
Certificate Name: app.gehnios.com
Domains: app.gehnios.com bi.gehnios.com
Expiry Date: 2019-06-04 23:51:53+00:00 (VALID: 77 days)
Certificate Path: /etc/letsencrypt/live/app.gehnios.com/fullchain.pem
Private Key Path: /etc/letsencrypt/live/app.gehnios.com/privkey.pem
Certificate Name: bi.gehnios.com
Domains: bi.gehnios.com
Expiry Date: 2019-06-04 23:52:03+00:00 (VALID: 77 days)
Certificate Path: /etc/letsencrypt/live/bi.gehnios.com/fullchain.pem
Private Key Path: /etc/letsencrypt/live/bi.gehnios.com/privkey.pem

I really appreciate your help as this a critical tool in our day to day operation…