Album Artwork not always displaying on Apple TV

I've been using Apple TV for several years now and have made sure all of my music in iTunes has album artwork and all was good until yesterday. Suddenly when I am playing my music on shuffle on Apple TV artwork is not displaying for some albums. I've checked in iTunes and the album artwork is present, the album artwork even shows up on Apple TV when you search and get a preview of the album artwork, it just doesn't seem to show up when you are actually playing the music.

I have Apple TV 2 and iTunes, which co-incidentally upgraded on Friday to the latest version.

Any suggestions to get my album artwork working again would be greatly appreciated. Thanks.