This site is being deprecated.
Please see the official X‑Plane Support page for help.
Please check the nullzone tab in the joystick & equipment screen. Make sure the sliders at the top are centered, and that the nullzone slider is full left for 0%. If those settings got changed somehow, it would definitely affect how your joystick works with X-Plane.
If that doesn't help, here is a section of the manual with some additional troubleshooting steps.
This site is no longer being actively maintained.