Site stopped working when I enabled cloudflare

Site worked perfectly prior connecting directly to account via domain name.

Enabled cloudflare, site now produces 403 "You don't have permission to access / on this server."

Connecting directly to the IP address still works perfectly. The account is on its own IP if that matters.

I'd be happy to share domain/IP address via PM but don't want it public/forever.

Thanks for any help you can provide

Check webserver logs for your domain for possible clues.