When I am searching on a term, duplicates of the same track are sometimes returned. In this example, 2 duplicates of each track are returned. In other examples, 4 duplicates of the same track are returned.

These point back to the same track when viewed in "properties".
A random search on another term "voodoo" turned up 58 tracks, but no duplicates.
Again, searching on "Calloway" for a second time, MediaMonkey does not return duplcates.
I can not identify what causes the duplicate search returns, or why in some cases 2 track duplicates are returned, and in others 3 or 4 track duplicates. Also as noted doing the same search "may" or "may not" result in duplicates.