artwork for new albums will not display

I've been using iTunes to host my own personal music (burned from CDs) for well over 5 years. My collection is hosted on a personal Windows 8.1 computer at home and an office computer with Windows 7 (Enterprise) at work.

The issue is that sometime since upgrading to version 12 this year, I am no longer able to get artwork to display for NEW CDs that I have imported since adopting version 12 (i.e. Tame Impala's "Currents", Wilco's "Star Wars", The Dead Weather's "Dodge and Burn" - all have come out recently and all have been imported since adopting version 12). Even though the artwork for these albums is available in iTunes, I receive the error message that this artwork cannot be found.

To contrast that, I recently imported Rush's older "2112" CD into iTunes, and iTunes found and displayed the artwork for that album.

I've tried deleting the iTunes artwork cache (http://www.mcelhearn.com/deleting-the-itunes-album-artwork-cache-folder-may-reso lve-problems-with-album-art-displaying/), but no luck.

I'm not sure what has changed since adopting iTunes 12, but if anyone has any suggestions, I'd greatly appreciated the help. Thanks - Eric

p.s. Current iTunes version is 12.3.0.44