Artwork not showing

[radiante]

Hi everyone.
I'm having a very similar problem. I use the Heos app to play files (stored on my NAS) through my Denon stereo. Until a couple of months ago, everything worked perfectly, but now the file covers only appear the first time. If I exit the disk and re-enter, the song images no longer appear.
Let me explain: the cover art for each song is tagged inside the song file itself in 500x500 jpeg format.
Using other apps (such as "hi-fi cast"), everything works perfectly.
I don't understand what the problem could be.