I am getting 522 for one of application.
Here is the setup I am using.
DNS is transfer from Namecheap to Cloudflare.
The main application with domain is hosted at Namecheap which is working perfectly.
I create a subdomain and host another application to another server. This server has h/w firewall configuration that only allow the https request from Cloudflare IPs. I upload the SSL at Plesk at origin server for this subdomain. But didn’t add this SSL at Cloudflare (not sure it required or not).
The connection from Cloudflare to Origin Server is using port 443 if I don’t upload custom SSL?
I have another application that is hosted on same origin server. It is working fine. The difference is this application hosted with different sub domain of different domain and has custom SSL uploaded at Cloudflare.
Could anyone tell me the possible reason?