The tiltable display (the upper screen):

Please check [TOUCH DISPLAY LOCK] in the [UTILITY] screen. If it is "LOCK", please select "UNLOCK".

How to touch display is different between the upper and the lower screens. Therefore even if you touch the screens in the same way, the reaction might be different. (For example, the lower screen reacts even you touch it with the tip of your nail, while the upper screen reacts only when you touch it with your ball of a finger.)

The main unit display (the lower screen):

Calibration adjustment of touch display could be incorrect. Adjust the touch display by using the [TOUCH DISPLAY CALIBRATION] settings in the [UTILITY] screen.