iPod Touch album art not displaying on device but *is* displayed when played via iTunes

5th Gen iPod Touch 64 GB . iOS 9.3.5. Loaded about 50 GB songs, most ripped from my own discs or downloaded from non-DRM sources... Amazon, Freegal. The album artwork displayed on the iPod, for probably a month or so. Then I added a few more albums, same process... iTunes, drag album to iPod, wait for sync. Suddenly none of the albums on my iPod display artwork. Notably, when I play the iPod through iTunes, the artwork *does* display in iTunes... and this is on my work PC, which is independent from my music collection at home. So my iPod has the artwork but just won't display it. Before I spend the time restoring and re-loading everything, is there an easier way to display the album art that is clearly on the device as we speak?