"Global Menu" doesn't work for Musescore 4 on linux.
A Global Menu is a linux term for a macOS -like app menu (File Edit View etc.) displayed in the top bar, rather than inside the window itself. I believe Musescore is built with Qt, and because of that seems to play well in that regard with KDE Plasma desktop with versions 2 and 3, but not the upcoming 4. The screen shots demonstrate how the three versions appear on Kubuntu 22.04. The last screen shot is how the Musescore 4 looks on macOS (pulled from a YT video). I would really love the Musescore 4 to support this feature on Linux!