I have figured out how to make this work without using the above network policy. OpenShift Local by default uses the weave network policy controller; which doesn’t support the usage of named ports inside network policies (as used within the helm chart). So By replacing the named ports with the actual port numbers I was able to resolve this issue.
A further issue I came accross is that the default-dns service for OpenShift local runs on port 5353 using the UDP protocol; instead of port 53.
You can find my project here: GitHub - gembaadvantage/z2jh-openshift: A kustomization of the z2jh project so that it works with OpenShift.