Monitor Watch Folder (the 3rd icon) purpose is to monitor a folder and process new folders as they are added to it, it doesn’t do anything with folders and files that already existed in the folder, and it will always continue to run until you stop it, at which point it will create the final report
Usually you will want to run Fix Songs (the 2nd icon) - this processes the folder selected immediately and then will finish once it has completed processing fields and created the final report.
