Currently on macOS when mouseMove is given an offscreen coordinate to move the mouse to, mouseMove will physically clamp to the edge of the screen, but if you try to grab the mouse location immediately after by using MouseInfo.getPointerInfo().getLocation() you will get the value of the offscreen point.

mouseMove should be updated to match other platforms and handle arguments beyond the maximum screen bounds by clamping the coordinates to their maximum values to prevent junk coordinates from being used in calculations.