I have noticed a strange thing with this song I have started to compose on Renoise 2.8, probably during alpha stage. (I have removed the samples because it is quite big): if you look into the “Song settings” tab, the “upgrade to latest version” button is present, although the song already uses the new commands sematic and lots of 2.8 features, not to mention that the portamento command also works as intended in newer versions.
song.xml states that the doc version is 37, exactly as in other songs which do not have this issue