Thx - got the AP part, 2 clicks on red button, and works independently of A/T.
I think the problem is the alignment of the throttle dial with the engine speed at the time of disengage of A/T to give it full range. This is an example screen shot - the joystick throttle dial is at 0 and the minimum engine speed is stuck at around 61% N1. I can move up to higher engine speeds, but not lower than 61%.
To work around it, I dialed the speed on MCP back to 100 knts with A/T engaged till engines idle to around 28% N1, and then move the joystick dial to 0, and then disengage A/T. Then I have full range of engine speed.
Is there any other way I can do this physical dial position to engine speed sync before disengaging? As a comparison, Toliss planes get around this with the detents (with audible clicks) and thus no problems with getting full range back.