This sounds like an issue with output overload which happens when every tiny movement of the analog stick causes the output to fire, which can quickly overwhelm the system. If you remove/disable the slider binding does everything else work OK? It would be good to narrow down the culprit. Also, just to check, does the system bog down or have any problem when you move the axis while the Key Recognition is disabled (keyboard button second to last in the toolbar)?
I cannot make it crash again (I move my hotas to other usb ports. But the Foxvox window is still freezing for a few seconds after I use any of my axis, and in game it creates some lag when I'm using fov zoom. I did not have the same behavior when using VA for example. And my control software was not running. It's like the app is reading input like crazy.