nx 1 internal touch act like a touchpad for the second

hello, in the moment we put in only the hdmi of our touch screen into a nx1, the cursor jumps to the second screen. after this the internal touch cursor is banned on second screen and we can control only things on second. the internal touch is like a touchpad for the second. if we put an additional mouse on a backside usb, it also only works on second screen!?
can anybody help?