I went through all the setup steps and selected '*' to listen on both
IPv4 and IPv6 interfaces. When Citadel started I was not able to
access it. I checked my netstat and all of the cit services are ONLY
listening on IPv6. I know this server has an IPv4 interface, as that
is the address I am using to SSH to it. Any ideas why it would only
be using IPv6?

That may be misleading. On a Linux system (unlike, say, OpenBSD) listening on IPv6 with an address like "*" will also make it listen on IPv4. Can you post the output of "ss -lt" so we can see where it thinks it's listening?

I suspect the problem might be somewhere else.