When using a dual touch screens on ubuntu, the touch may not be mapped correctly to the monitor and it may span both screens as input and only 1 monitor as an output.
Or simply touching any of them will result in having the input on the same screen (Relatively).

So, In order to apply a fix for this issue, The touch input should be mapped to the correct monitor

We may use 2 linux apps to list this info.
1. xinput is used for listing the input devices
2. xrandr is used to show/set the size, orientation and/or reflection of the outputs for a screen. It can also set the screen size.

user@ubuntu:~$ xinput
⎡ Virtual core pointer                    	id=2	[master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer              	id=4	[slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad              	id=18	[slave  pointer  (2)]
⎜   ↳ CoolTouch System             	        id=11	[slave  pointer  (2)]
⎜   ↳ SYNAPTICS Synaptics Large Touch Screen  	id=15	[slave  pointer  (2)]
⎣ Virtual core keyboard                   	id=3	[master keyboard (2)]
    ↳ Virtual core XTEST keyboard             	id=5	[slave  keyboard (3)]
    ↳ Power Button                            	id=6	[slave  keyboard (3)]
    ↳ Video Bus                               	id=7	[slave  keyboard (3)]
    ↳ Video Bus                               	id=8	[slave  keyboard (3)]
    ↳ Power Button                            	id=9	[slave  keyboard (3)]
    ↳ Integrated_Webcam_HD: Integrate         	id=10	[slave  keyboard (3)]
    ↳ MOSART Semi. 2.4G Keyboard Mouse        	id=12	[slave  keyboard (3)]
    ↳ Yubico Yubikey 4 OTP+U2F+CCID           	id=14	[slave  keyboard (3)]
    ↳ Dell WMI hotkeys                        	id=16	[slave  keyboard (3)]
    ↳ DELL Wireless hotkeys                   	id=19	[slave  keyboard (3)]
    ↳ MOSART Semi. 2.4G Keyboard Mouse        	id=20	[slave  keyboard (3)]

You can make sure of the name of the input device by disconnecting and reconnecting it.Then Note the device id value.
In this case our target system is:
↳ CoolTouch System id=11 [slave pointer (2)]

user@ubuntu:~$ xrandr
Screen 0: minimum 8 x 8, current 3968 x 1152, maximum 16384 x 16384
eDP-1-1 connected primary 2048x1152+1920+0 (normal left inverted right x axis y axis) 346mm x 194mm
   3200x1800     59.98 +  59.96    59.94  
   2880x1620     59.96    59.97  
   2560x1600     59.99    59.97  
   2560x1440     59.99    59.99    59.96    59.95  
   2048x1536     60.00  
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   2048x1152     59.99*   59.98    59.90    59.91  
   1920x1200     59.88    59.95  
   1920x1080     60.01    59.97    59.96    59.93  
   1600x1200     60.00  

HDMI-1-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1680x1050     59.88  
   1400x1050     59.95  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
  
DP-1-1 disconnected (normal left inverted right x axis y axis)
HDMI-1-2 disconnected (normal left inverted right x axis y axis)

The name of the output interface is the 1st reported value in each section of xrandr’s output.

In this case We’ll be using   HDMI-1-1

So, Mapping the  CoolTouch’s input to the monitor connected to the HDMI interface can be done using this command

xinput map-to-output 11 HDMI-1-1

The same strategy can be followed If you have more than 2 monitors.

This command is not persistent and it should be executed every time the pc is restated or locked.

So it could be added to en executable script and executed every time you log in to the system 

echo "xinput map-to-output 11 HDMI-1-1" > /usr/local/bin/align_touchinput
chmod +x /usr/local/bin/align_touchinput
cat << EOF > ~/.config/autostart/align_touchinput.desktop
[Desktop Entry]
Categories=System;Input;Touch
Comment=align touch input
Exec=/usr/local/bin/align_touchinput
Name=align_touchinput
Type=Application
EOF