I got your Bug Report and I can confirm that there's only one controller detected by the game.
If not already tried, unplug & replug, and restart your PC.
If it doesn't help, change this line in your XKT.ini, under [Menu], from :
JoyDeadZone = 0.5
to :
JoyDeadZone = 0.95
(HowTo =>
topic19-32161.php )
Then launch the game to see if it helps.
Last thing, try to disable/enable Steam Input for the game.