If you find that you can not fly vertically with the ART Flystick you should check the following:
-Is character controller disabled? This can be found in the main tool bar
-Is Lock Camera Altitude When Tracked disabled? This can be found in Settings (F6) > Tracking > General
-Is the Translation Mode in the Joystick Navigator Tool set to Fly in Controller Direction? This can be found in the Developer tab under root > Users > Username > ToolBox > JoystickNavigatorTool