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.