Thanks for creating a post on community - we’re sorry you’ve ran into issues with the display of album covers. We’d love to help sort this out.
Could you please also let us know the source of the albums in your Roon library? Are they from your local library or TIDAL/Qobuz?
If you search for the album, is the artwork displayed?
Have you completely rebooted your Roon Core? By that I mean, hold down the power button until the Core is turned off, unplug it for about 2-3 minutes, plug it back in and restart it?
Thanks in advance