If you have the latest vorpX installed, it should just work. You can check the current version in the bottom/left corner of the game window, should be 21.1.1.
Also make sure to reset the profile to default in the config app.
If TrackIR still does not work for you afterwards, you can also do it the other way around and disable it in the vorpX menu instead of enabling it in the game. That way vorpX would do what it did before and simulate a gamepad with head tracking.
In that case you might also want to switch the ‘Play Style’ option to immersive screen. The gamepad emulation is a bit too laggy to be comfortable in FullVR mode.