Hello, this problem has already been reported several times, Roon 1.8 - View More sometimes not available in Focus [Ticket In] for instance 6 days ago. As many people report problems with Roon 1.8, it is difficult to search for similar issues.
I have exactly the same problem, with a Windows PC or an Android tablet. But with my Android phone, “view more” is always working, so I can use it, but I am waiting for a quick fix!
Best regards,
Sylvain