[BTT 3.553 (1963), macOS 10.15.7, MacBook Pro 15-inch, 2019, MacBookPro15,3]
Not sure when this stopped working, but when I am playing music from Music.app and playing songs from a Radio "station," the Album Art icon is not populated in my Now Playing Widget. (Album art does appear when I play songs from my local library which do have AA.) Can't seem to get it to appear - stopped/restarted BTT, rebooted, stopped/restarted the song.