Run the attached application on macOS. Observe the white label resized to its preferred size and the scene/stage dimensions printed to stdout:

scene.width=150.0
scene.height=17.0
stage.width=150.0
stage.height=17.0

Expected behavior: Stage and Scene dimensions are set to the dimensions of the primary Screen.

Run the same code on Windows. Observe the label taking full screen *as expected*, and the stdout containing the screen sizes *as expected*:

scene.width=146.0
scene.height=17.0
stage.width=146.0
stage.height=17.0
stage.width=1920.0
stage.height=1080.0
scene.width=1920.0
scene.height=1080.0
stage.width=146.0
stage.height=17.0
scene.width=146.0
scene.height=17.0

Notice that Swing in fullscreen mode reports the Window dimensions corresponding to the screen size as expected on both Windows and macOS.