I had to Gang two Channels for Stereo Input Feed
first I ganged the parameters without the gate
than I set up the ducker on one channel and changed in that channel the key input to a MonoGrp and then I remembered that I left the gang without the gate
so I ganged the gate also
and the other channel didn’t used the different key input, it was on self keyed, not good for ducking 
I think the gang in the ducker should include the key input