I have the joystick functioning perfectly. Make sure the exact name windows assigns to the joystick because that is the one you have to pass to MP on the startup line.
The name of the joystick you pass to MP on the line it is not needed for the joystick to work it just enables joystick on startup.
The messages the joystick sends to arducopter i don’t think are MANUAL_CONTROL but RC_OVERRIDE.
Corrado