My domain is takemytickets.co.in, where I tried to create a subdomain for this domain and the subdomain should point to a server in aws ec2. So, I used CNAME record for this. Below is the configuration.
521 error referring to webserver down.
You may want to check if the origin servers block Cloudflare IPs or Port 443 and Port 80. Cloudflare IP range
I would strongly suggest you to check with the origin server provider.
I’ve run test to the CNAME target IP, and it’s showing port 443 (tcp) failed: Connection refused and Failed to connect to x.x.x.x port 443 after 220 ms: Couldn't connect to server.
Both Port 443 and Port 80 showing connection refused.