The result of the command Manual Correct Metadata from MusicBrainz shows a list of files, which are matches of the song in question.
In the resulting window is a column named Acoustid ID. The field Acoustid ID of the match candidates is not filled up, despite they have an acoustid.
Manual Correct Metadata from MusicBrainz
Isn’t is because their acoustid does not match the acoustid of your song ?