Hi there jdoe1979,
FQDN is currently required for the full operation of the blade.
You can enable Zero Phishing without HTTPSi but that would negate most of the benefit the blade provides as most websites are HTTPS nowadays.
If you want to fix your issue in the lab, you can either configure a new record in your DNS server so the end clients will be able to resolve the FQDN entered in Zero Phishing configuration or you can manually edit the hosts file on your client/s with the FQDN you entered in Zero Phishing configuration and the IP of the interface facing the client.
We are working on a solution that will require no configuration from the admin and it will just be click and play, so to speak.
Let me know if you have any more questions.