Long-time user of Picard here. I have been facing this problem past month or so. I would drag the files into Picard, save the findings and then clear from Picard. When I check the file in Windows Explorer or my music player, MusicBee, the album tags are not visible. Then when I drag the file again into Picard, the file go into the right panel with the previous search results matching. I “save” again and the album is stored in this second pass in the file.