Suddenly 2 of my WordPress sites could not communicate with Cloudflare via Cloudflare plugin.
I even enable APO to test it but no.
I disabled all the plugins, change theme template, turn off firewall, reboot server, reinstall WordPress latest or previous version, re install Cloudflare plugin etc but nothing works.
I can see that even with WordPress plugin installed or not, Cloudflare api does not communicate with my domain anymore.
My domains are hosted in contabo server, I have check about ip blacklist etc with no result!
Either way i was not using the Cloudflare plugin before, only a third partie, i just installed to confirm the issue with Cloudflare CDN because for me it stopped working with all the plugins!