I’ve been having all manner of issues with Playlists created in iTunes and then imported into Sonos.
Both Apple and Sonos seem to be updating their software without consideration of this integration feature. Every time the software asks to update form either company, I am worried it will break everything (again).
Now, I can get Sonos to read the XML playlists inside an iTunes library sitting on my NAS. I can see the playlist under External Playlists, and the individual song filenames (with MP3 extensions). However, when it tries to play the songs from the playlist, access is denied. When I instead Search for the individual song, I get the Song fine with all metadata. This kinda defeats the point of a playlist. Very annoying.