If I understand your problem correctly, it’s because both of these conditions exist. Some songs/tracks are recognized by Roon as compositions and then they are counted as performances and listed in the counts. Some are not.
Sometimes it’s because a composer credit is missing from a track, then it helps to add one.
Sometimes with local albums (even if the tracks have composers) it helps to add a streaming version of the album and suddenly the tracks count as compositions.
Sometimes, it seems like nothing helps