Artwork choosen for the albums on the music library sometimes are pixelated ones

Hello, if someone could help me it would be nice. My question is, everytime i make a “Music” library, plex chooses the artwork on the albums that often is the bad one and not the one with high resolution, is this normal? All my albuns on itunes are with the perfect artwork on them. To exemplify, look at this: some of those albums are with the artwork with pixelated resolution on them, on other note, when I see the information, they have the original artwork with high resolution but is not choosen by the system, what should I do? is this normal?



Also possible:
the pixelated cover comes either from within your files (so-called embedded cover art)
or
it comes from cover art files which were left by Windows Media Player (smallthumb.jpg, folder.jpg and similar)

see this thread https://forums.plex.tv/discussion/comment/1173370/#Comment_1173370

The order of the lines under
Settings - Server - Agents - Albums
is important.
Particularly whether the line ‘Local Media Assets’ is in the topmost position or not.
If it is topmost, cover art is taken primarily from cover art files in the same folder as your media files.
Then embedded cover art is used.
Onlyl after that follow the online metadata sources.

You can “prefer” the online metadata sources
by moving the line ‘Local Media Assets’ downwards.
However, this also prefers all the other metadata from the online sources (last.fm, Gracenote) which often don’t fit your particular version of the album or contain errors.
So my recommendation is to clean out these hidden, low-resolution cover art files and replace them with high-resolution cover art files which you selected yourself.

Or you edit each album within Plex and pick the best quality cover art there.