Created attachment 863794 [details]
xrandr

When plugging a external touch screen into a HP Omen Notebook with USB-C, the
display is found (although DPI is not reset for the display, and stays like the
original monitor). However, the resolution of the touch field on the touch
screen is adopted to both screens, which results in differences between touch
position and screen position.

If touching the external touch screen at the left edge, the cursor goes to the
laptop screen completely left, while when touching the external screen
completely right, it actually hits the position on the screen. 

In order to use the screen, you would have to guess where the cursor would
appear which is at least unexpected.

Adding respective files to this report.