Thanks for the suggestion.
I use OpenWebStart to run Start.jnlp with the OpenJdk: WHICH STILL DOES NOT LAUNCH THE ADMIN CONSOLE.
I have now tried http://eisy.local:8080/admin.jnlp with the OpenWebStart and it successfully opens the admin console on my Win10 PC.
I shall now try the next stage of development using the eisy.
For others: OpenWebStart is from Karakun (I use version 1.11.0) from: https://openwebstart.com/
OpenJdk from: https://openjdk.org/projects/jdk/23/