Hi Geoff, yes Merge does solve it but there are a couple of reasons I’m trying to solve the “root problem” instead.
(1) There are other problems, e.g. albums not sorted properly and compilation albums not showing album artist as Various Artists even though they’ve been tagged as such. Hence I believe there’s an underlying Metadata issue. If solved, this should resolve all these other problems. See screenshot below.
(2) This is really just an emotional reason… as I hope to pay for Roon (I’m still on a free trial now), I’m expecting it to work.
Besides, I don’t have issues when I view these albums with (i) foobar2000, (ii) Synology’s Media Server or (iii) Plex (I omitted to mention earlier that I’ve Plex media server installed and running too).
Hence, I’m thinking that this is a Roon issue (solvable, I hope!).
Below is a screenshot of My Albums Sorted by artist. Under Settings-General, Name for compilation sorting is “Use album title”. Show hidden tracks and albums = “No”.
(AAA) As shown, a bunch of albums with Various Artists inexplicably appear at the top, right after 10,000 Maniacs… and before A-Ha and Aaron Neville. Why?
Another bunch of Various Artists albums appear under “V” some before and some after Van Morrison; while some appeared after “W” when sorted alphabetically 
I believe Roon is not reading the metadata correctly… or perhaps my metadata is corrupted… but Mp3tag doesn’t show any corruption. I tag and check all my albums using Mp3tag.
(BBB) You’ll also see below that the Billboard 1970 album is duplicated. The second one has just one song… but with exactly the same names for Album and Album Artist. I’ve this problem scattered all over, even though I’ve checked their metadata using Mp3tag.
Is there another field that Roon is reading from? Is there another tagging software that is more “compatible” with Roon which I should use?
Many thanks!