This is one of the tracks where I noticed this:
That Roon plays twice (as Parts 1 and 2) - Why? 
It seems that you have two different files: the “kbps” value differs for the two.
I noticed the same.
Apparently you are right - there are 2 files of the same track in the same folder:
- A Flock of Seagulls - Nightmares.mp3 and
- A Flock Of Seagulls - The Best Of A Flock Of Seagulls - Nightmares.mp3
but still, why play both, one after the other, in Library Radio ?
And why does it display them like they are 2 tracks of Classical Music?
It seems to be a track identification bug.
I saw the same behavior in the case of a playlist that contains 2 tracks from the same Qobuz album. Tracks have the same name, and in the album one is the first track and the other is the last track (there are versions in different languages).
However, in the playlist Roon sings them as if they were a single track with two parts (although in the playlist they appear as separate tracks).
Edited:
apparently Roon got disconnected from Tidal after the latest upgrade
ok - this is weird.
With Tidal disconnected, Roon showed these 2 Albums in my Library:
Now with Tidal reconnected, they are gone:
You are comparing two different things: the search result with the artist’s home page. These look different with or without the Tidal connection.
Is this an identified album? If Roon identifies the album then it will, generally, do the right thing.
If it cannot identify the album then, basically, all bets are off. It has no idea what its playing and simply treats everything in that directory as individual tracks with no reference or concern if they may be related, the same, or different.
The Artist (Nena) is/was identified in 2 compilations.
Are talking about Nena or the Flock of Seagulls tracks? I was referring to Flock of Seagulls tracks.
That as well as AC/DC further down are both identified correctly - try what I did with the AC/DC track yourself in your library