Cloudflare don't work with a website with dedicated IP

[cosmin]

An account with dedicated IP and Cloduflare show only the error

500 Internal Server Error
openresty

If I changed the dedicate IP and put the main server IP (also changed these in Cloudflare account) the website works perfect. The same problem with Ips from another two classes. So the problem is on because the account has a dedicated IP.

Any idea?
Many thanks!

 

[kodeslogic]

After switching to the dedicated IP in WHM make sure you also update the IP addresses in your Cloudflare DNS app. To modify DNS record content in the Cloudflare DNS app, click on the IP address, and enter the new IP address.

If still an error after modifying IP in Cloudflare DNS is the site working fine without Cloudflare nameservers?

 

[cosmin]

I found the problem, come from this settings in Imunify360:

Detect IPs behind CDN
Allows to recognize and block IPs with suspicious activity behind CloudFlare and MaxCDN

Very strange, why works with main IP....

 

[cPanelLauren]

Glad to see you were able to resolve the issue.