I’ve noticed in the current public hosted build of the Web client that if I browse around in my music library, sooner or later the “similar artists” gets “stuck”.
Like this: I browse a metal artist. They have so and so similar artists. Now I browse a pop artist, and they will have the same similar artists as the metal band. I browse more artists, and they all have the same similar artists as the metal band. Restarting Plex Web immediately fixes this, until it happens again.
This happens for a friend too, in a different music library. This didn’t happen on the last versions, so it’s probably related only to the latest version.