Audio folder thumbnail

All my mp3 have embedded album art which shows up fine.  Each audio folder has a folder.jpg - yet I can’t see album art when in album thumbnail view.  I am using a WDAVN00BN with the latest firmware and I thought it was supposed to show the album art …Am I doing something wrong?  Was there a firmware where folder.jpg did show for each album when in album thumbnail view? 

I have the same issue.