macOS Music app: lots of duplicate tracks, and cloud sync problems

I use the macOS Music app, and am subscribed to iTunes Match (but not Apple Music). As I peruse some of the custom music songs I've added to iTunes/Music over the years, I'm now finding that many of them are appearing as duplicates, as shown in the attached screenshot.

One version is shown with a download symbol next to it. But it's the same track. Why does it display this way and is there a way to consolidate its display?

In addition, when I mouseover the tracks that DON'T have a download arrow, then I get a crossed-out cloud symbol. I think this means the track can't be synced to iTunes Match. But it's not clear why, since the track DOES appear to be in iTunes Match (??)

Please help me understand this: