In Dsub 4.x if you pressed "Delete Cache" when viewing a list of artists in Offline mode, then that artist and all albums and songs beneath him were deleted.
Now in Dsub 5.0, it only works if there are no albums and songs beneath that artist, otherwise nothing happens. It is necessary to go into each album and delete the songs in that album, then delete the albums, and finally delete the artist.
The actions in 4.x are more intuitive and should be reinstated in v5.1