When I move the knobs in the plug-in the parameter changes are sent to the VST device in Ableton Live (running Mac El Capitan and Live 9.6) but when I change the parameter by moving knobs on the synth it only changes in the plug-in but is not sent to Ableton Live VST device.
See this Video:
https://dl.dropboxusercontent.com/u/5057386/Sub37%20beta/Hardware%20knob%20does%20not%20send%20VST%20param%20to%20VST%20device%20in%20ableton.mov
At first I move the Cutoff frequency with the mouse and the paramter changes in live. Then I use the synth knob and only the value in the plug-in changes.
It seems like the plug-in do not pass parameter changes on to the DAW when received as MIDI.