iPhone playlist deletion

Hi,
I want to delete On the iPhone Playlists that I have created and no longer want, and cannot find out how to do it.

On the iPhone Sonos controller the top level menu lists; Sonos Favorites, Sonos Playlists, On this iPhone, Radio by Tunein, etc.

Clicking the "On this iPhone" item gets you to a next level menu; "Playlists, Artists, Albums, etc.

So there are two playlists; the Sonos Playlists and the On the iPhone Playlists.

I can delete entries in the Sonos Playlists but not in the On the iPhone Playlists.

Deleting Sonos Playlists entries involves clicking the ... item at the top right of the screen listing the playlists which gives you the option to Edit Playlist. You select this and can then select a playlist to delete.

Trying to delete entries in the On the iPhone Playlists seems impossible to do.

When you select the On the iPhone Playlists option you get a list of playlist entries under a Playlists heading but there is no ... selection item at the top right. Selecting a playlist entry gets you the items on that playlist with ... selection items to the right of the playlist title and the playlist entries, but none of these, if selected, give you a delete option, neither for the individual playlist entries nor for the playlist as a whole.

I want to delete On the iPhone Playlists that I have created and no longer want, and cannot do it.

I have removed and re-installed the Sonos controller app on my iPhone, connecting to an existing Sonos system upon re-installation, and the old On the iPhone Playlists come back.

How, please, can I delete On the iPhone Playlists that I have created and no longer want?

Thank you for any help any community user can offer.

Chris.