Some music playlists duplicated as audiobook playlists

Hi,

Some of my hundreds of music playlists on iTunes have been replicated as empty audiobook playlists. If I try and delete the audiobook playlist in iTunes it deletes the music playlist as well. If I try and remove the playlist by unticking the playlist from my iPhone's music list and then syncing it removes them files. However on my iPhone (new iPhone SE2) the playlist remains as a music playlist but with the songs greyed out and unplayable. IF I sync my playlist again my PC thinks that I've deleted the contents of the playlist and removes them from iTunes on my PC. None of these syncing problems occur with the iTunes music playlists that aren't duplicared as iTunes audiobook playlists.

So can anyone suggest:

a) a way or removing the playlist in audiobooks on my PC's iTunes without also deleting the playlist in music on my PC's iTunes

b) a way of removing the ghostly (audiobook?) playlists from my iPhone so I can resync everything with a clean slate (I'm not keen to do a fatory reset as I need to make sure all my photos are in iCloud beforehand).

Thanks!