in Plex Web > music > artists, shuffle is the first item on the menu
on the artist page, you just hit PLAY and it shuffles the artists tracks
on ios, on the artist page, tap the 3 dots > shuffle
on plexamp (plex pass required) > artist page > tap play (shuffles)
you can also have smart playlists that are shuffled see also @ [TIP] --- how to create an autoplaylist with random sort
