I have the same problem. I have spent the last 4 days trying to get mine to work. I can get it to work in demos but it will not interface with vjoy. I have tried the newest drivers, the old ones mention above and nothing I do gets this working in Elite dangerous. I returned my Irtrack 5 for this and starting to feel that was a mistake.
I also have an X52 Pro that I believe is conflicting in some way with Vjoy. Each time I install Vjoy I notice the lights on my throttle go out. (Lights on the flight stick stay on). When in screen extensions and I try to set the enable disable key or the screen centering option it always says Joystick 27 + (my key choice). Not sure if Joystick 27 is Vjoy or my X52. When I remove the X52 and drivers from the system Joystick 27 goes away and I can Select just my key choice.
Other things I have tried, uninstalling and reinstalling elite dangerous and ED: Horizons. I have tried manually changing my bindings in the config file.
One thing I noticed in Vjoy monitor, X,Y and Z all have a red input level of 50% that never change. If I have the X52 removed then inputs 1 to 8 are also discovered. With the X52 installed no inputs are checked and only X and Y have input levels in red.
I am about to pack this up and request a refund, this is pretty ridiculous how much time I have wasted trying to get something that should work out of the box working.