I'm using mp3 files. I discovered what to do.
When writing the artist on MB, I saw the file was not changed... the file outside MB, the file on explorer. And google drive does not do any sync, cause nothing was changed in the mp3 file. I guessed the informations on tags made inside MB was not attached in the real file on explorer. And when reescaning files, my tags editions was lost.
But, today, when doing the same and playing the music, in the same moment music are played, google drive sync the file... and the information on file explorer changes too.
It seems that my Tags editions only take effect outside MB when the songs are played. Dont know why, but at least I know what to do. Thanks for attention