SSL/TLS, Origin Certificates and 502 Bad Gateway

May I ask have you tried checking with the steps from below article?

Therefore, have you checked your access or error log at your origin host/server for any clue?

Is your app working over a supported and compatible port with Cloudflare proxy mode :orange:?:

If you installed correctly the Cloudflare Origin CA Certificate at cPanel, you have got the green lock and saying it expires in 15 years (or shorther if you selected), correct?

May I ask if you have got some firewall installed at cPanel, like Imunify360 od ModSecurity enabled?

Nevertheless, do not skip below step and kindly re-check if Cloudflare is allowed to connect to your origin host to as follows in the below article:

Cloudflare IP addresses list can be found here: