iTunes artwork not showing

For years, I had this problem

Now with a brand new iPhone X with a great screen, I want to find the problem and be able to enjoy those artwork on music on iPhone.

on iTunes

example, in album view, many artwork are missing.

I have to do a Get info, click on artwork , select it, then it will show on iTunes

on iPhone

a large number of artwork and not showing up on the iPhone that are showing on iTunes

I have try so many things

rebuilt library etc.

My last try was with applescript, it plays each song for 3 seconds

because sometime, artwork appear when I play the song

but It did not seems to help.

I have a very large library and half of them are rated with the 1 to 5 system rating and have lyrics in most of them.

I did a search in discussion and like me, many others had this problem over the years, but could not find a solution in those that worked for me.

Any help would be appreciate

thank you