pfSense

I have a docker container running with dynamic DNS I am trying to portforward out.
The name registry-sysd.containers.ikioma resolves to 192.168.81.0

I have the following DNS records:

registry-sysd.containers.ikioma. 60 IN  CNAME   f93225833927.containers.ikioma.
f93225833927.containers.ikioma.  60 IN  A       192.168.81.0

I have an alias called registryd which points to the above domain name.
The table in [Diagnostics -> Tables -> registryd] has the IP address 192.168.81.0. (DNS resolves correctly)

I have a port forwarding rule

IF: Wan,  Proto: TCP,  Src: Wan Address : 5000,  Dst: registryd : 5000

It has an autogenerated associated filter rule:

IF: Wan,  Proto: TCP,  Src: Any,                 Dst:  registryd : 5000 

If I try to access mydomain:5000 with a browser it gives ERR_CONNECTION_TIMED_OUT.

However if I change the alias from registry-sysd.containers.ikioma to 192.168.81.0 and apply I can access the service.