Clients utilizing CloudFlare as a DNS provider should be aware of issues with the feature they provide known as Orange clouding or DNS Proxy. Their documentation recommends this feature as a best practice for protection against DDOS and other performance optimization. However, this feature interferes with the ability for ThoughtFarmer to securely determine the origin request and will cause users to not be able to authenticate.
CloudFlare DNS Only setup
When creating CNAMEs for ThoughtFarmer for your custom URL to our ThoughtFarmer one please always ensure that the proxy is set to DNS Only. If it says "Proxied" users will have issues authenticating.