CF work well but South Africa

Hi All,
we are using cf for many sites. In this week the sites stop working from South Africa. From other countries working well.
I found this in the server log:
client denied by server configuration: /var/www/xmlrpc.php
I blocked the xmlrpc but same result.
What should I do?

A 522 error typically happens when Cloudflare requests to the origin (your webserver) get blocked. Review the suggestions in this Community Tip for troubleshooting ideas.

I checked many times. The cf IPs not blocked by anything (directly added all). The request can reach the server with error message as I mention first. The xmlrpc not working that sites. It looks the cf server from South Africa send a bad request to my server.