By calibration touch screen it will reset all the touch screen position. Two ways to do that:

1) when you power on scanner, you will see a progress bar "Touch here to calibrate your screen". Click and hold until you enter Calibration Mode as following screen. If you go into Home Screen, please repeat power off and on agatin

2) select Settings and Calibration.

when you are in Calibration Mode, just tab on + sign on four each corner to calibrate. Once done, it will bring you back to home screen.