Note that it is not a test bug but testing-related deficiency in a tool.

Some -- I dare say many or even most -- Apple keyboards require an extra key to press for a "functional" key. Say, to press F10 one should use fn+F10, otherwise something else happens, usually Mute state of a speaker toggled.
Now, a swing context menu has a working shortcut SHIFT+F10. For a human, there's no problem to press three keys instead of two but for Robot it's really hard since Fn key is unaccessible, it has no keycode and no unicode value (thus, extended keycode).

In addition, when you press and release Fn key, you receive 2 KEY_PRESSED and nothing else.

Try as an example the attached simple code.