In APT, which drivers are you using? When I Shift+Left Click in APT, I choose "ASCOM," then ASCOM driver window will open and there should be an option to select "ZWO Camera" when you click on properties, if both ASI cameras are connected, you should be able to see a drop down menu for both ASI Cameras, select the 183MC pro camera if you see it and should be able to change settings for it.