If this is not a physical issue like - which it may not be as the LED Backlight can be seen by looking down the front side of the LCD. Then try updating the drivers. I was running Windows 10 Pro without flaw. Reinstalling the OS even before the fix did increase the sensitivity in the Multi Touch Display. However the MX4 was a Japanese model and had a Win 8.1 Load all in Japanese. I reloaded with Win 10 US and updated the drivers.
Drivers can be found here: http://pc-dl.panasonic.co.jp/itn/driver ... tml#CF-MX4
Any questions just ask - I have owned 3 CF-AX2's, 1 CF-MX4, 1 CF-AX3, and now currently own a brand new CF-RZ5 (These are all Panasonic Let's Note Ultrabooks)