When you select a particular artist in Tidal you can then choose between Top tracks, Albums, EPs and singles, Playlists, Artist radio and Compilations.
When selecting Artists radio you are taken to a playlist with no way of starting it. You can only select a track.
Clicking the first track does not begin playing everything and adds only that one track to your Sonos playlist.
Tidal Artist Radio worked until a few days ago, something has changed.