If you installed Smartpropolus and/or vJoy you could try uninstalling that, it might cause a conflict. Also, make sure you don't have any other joysticks/controllers connected, that might cause a conflict.
As for the AT9 - most people generally have success using a 22-in-1 universal flight simulator dongle or similar when connecting the radios. Don't know if it works with the Radiolink AT9 though. If it has a standard 3.5mm trainer port you could try to use that one as described in the manual