Okay finally! Thanks to a post from 2015 (phew...)
I had to go to device manager, uninstall the 3 Throttle plugins, remove the drivers, shut off the throttle, restart, replug and now I have perfect control over the throttle again.
For some reason, it appears to be the drivers getting corrutped in some manner. I installed a new headset yesterday, that's what might have triggered the bug!
