I often want to open mp3tag on a specific folder by right-clicking on the folder name in Finder, and selecting the "Services/Open in Mp3Tag" menu option. However, this doesn't work - mp3tag opens on the the previously-opened folder, not the open I selected from Finder. It seems the only way to change folders is with "File/Open..." inside Mp3Tag itself?
It's supposed to be working and it works on macOS Catalina 10.15.7 and on the upcoming macOS Monterey 12. However, recent versions of macOS Big Sur (I'm testing with 11.6) have broken the detection whether the app was started via the Services menu or if it's a default launch.
I've already reported this to Apple, but haven't received any feedback on that. Based on my experiences, it's unlikely to be fixed with an upcoming version of Big Sur.
To workaround this issue, you can change Preferences → General → Startup Folder to None.
Thanks, that works great!