Sorted! 
As soon as I reset ROCK back to DCHP I can now get all my radio stations! It’s amazing how we forget these changes we make to solve one problem, when looking for a solution to a new problem these changes have made!
All I wanted to do was get ARC up and running to test (I have no use for mobile ROON but thought I would see what all the fuss was about!) and I knew it had ‘double NAT’ issues that I can’t solve (ISP ‘bridge mode’ breaks my wifi router?) so first job in the instructions was set a static IP address for the ROCK server… beware all thee who follow after me! 