I apologize if this seems easy, but I don't get it. And by folder I do mean thumbnail
Highlight the 10 Allman Brothers Tracks...right click...edit....Artist....Allman Brothers...save
Look....Allman Brothers thumbnail...with 10 files appears...awesome!!!!!
Remove flash drive....reinstall flash drive.....Allman Brothers thumbnail gone....same 10 tracks are right where they were...
I did this with several of the others included track title, artist, etc....everything was going well and appearing in the thumbnail section....close out musicbee and open later...everything reverted back to unknown