Is the IP address of the pfSense WAN interface a public IP address or a private IP address? This affects how pfSense decides if the address registration needs to be updated.
Shouldn't I see the WAN IP address listed there in green?
Maybe you haven't provided the correct details to login to the dynamic DNS to change your registration. What service are you using?
If the ISP changes my IP address I think that the DNS will not be updated and I will no longer be able to connect by domain name. What do you guys/girls think?
It works for me.