I just copied my initial post as support request. Let’s see if that helps.
I also tried Marantz’s support but their “Contact us” page looks like this 
Just go here… https://support-uk.marantz.com/app/ask
Thank you for the hint @maddib - I just did that. Let’s wait and see if/how Marantz responds.
It is confusing, but, if you look at the Marantz website for that unit…
It clearly shows Roon Tested which means it does not have the Roon Network code
Personally, I’d return it. There have been too many times where manufacturer’s have promised Roon Ready and never delivered.