Cheers, at this stage I would have to set up a test sections as the docs are minutes of private meetings.
However I have realised that if I set the menu linked on the list to public the google preview works, but if I set the menu link to registered users only then the preview does not work. In hindsight I am thinking that would be expected as the viewer would be a public link, am I correct in thinking that.
I am happy to set up a testing section as needed if that is not the expected result.
Thanks for your reply.
PS just testing a bit more, if I set everything on the advance listing backend access to registered the preview works fine if I leave the menu item at public, but when changing the menu item access to registered I only see the page source in the preview page you may be able to view this here: