The default style for MenuItem headers without the ripple layer correctly sets RecognizeAccessKey (MenuItem.xaml#L140@5515312), however the ripple layer header template does not (MenuItem.xaml#L88@5515312), resulting in menu items with no children and a keyboard accelerator key displaying a literal underscore on mouse down.
The default style for
MenuItem
headers without the ripple layer correctly setsRecognizeAccessKey
(MenuItem.xaml#L140@5515312), however the ripple layer header template does not (MenuItem.xaml#L88@5515312), resulting in menu items with no children and a keyboard accelerator key displaying a literal underscore on mouse down.