Popular Tracks - How does it work and what am I missing?

Have already tried that, and no dice

The list of things tried:

Unmatch and rematch - album level
Unmatch and rematch - artist level
Change case to exactly match last.fm on both album and track
Plex dance the entire artist, removing the cached data and completely reimporting

So far, nothing. I also noticed that some new artists now seem to pick up last.fm artist recommendations as a fall back, but this seems spotty as well

If I can get a clear set of prerequisites needed for a match to happen on popular tracks (along with recommended artists if my above suspicion is correct) then that would help