Thanks for the reply. Android version is 8.0.0. Poweramp build is 823. Album art is embedded. There aren't any image files within my music files..... meaning the album art is embedded and not sitting in folders.
When I first saw the issue, I wondered if it was a refresh problem. I thought swiping forward a few songs and then swiping back to the problem song/album art might get it to refresh and bring up the album art, but it doesn't. Once the art for a particular song stops displaying, the only way I found to get it back is to long press the art area, select album art and then