While scanning my Playlists does not appear in Roon. Playlists are stored in the root of my music folder on my synology DS918+. My music files are stored in different (sub)folders in the same music folder.
Some example of my playlist content: #EXTM3U #EXTINF:334,The Afghan Whigs - John The Baptist
Flac/The Afghan Whigs/1965/07. John The Baptist.flac #EXTINF:275,Antony and the Johnsons - Soft Black Stars
MP3/Antony and the Johnsons/2001 - I Fell In Love with a Dead Boy (EP)/03 Soft Black Stars.mp3 #EXTINF:247,Balthazar - You’re So Real
Flac/Balthazar/2019 - Fever/11 - You’re So Real.flac
I did read the article. I fixed it however. I made a new subfolder in the music root folder. And move all music subfolders and playlists to the new folder. I don’t know what makes the difference but this works for me.