I have the same issue! I really liked this chromebook, my first. I do not recall how long ago the issue began, but thankfully, it does not impact as much of my screen as the other poster mentioned. A little under an inch of the entire left border of my screen is unresponsive.
I've gotten creative with ways around this in tablet mode (rotating the device so I can use a different part of the screen, going into split screen mode and dragging a window to the unaffected part of the screen, etc.)
The most annoying defect is when the touch screen gets erratic and responds incorrectly when I tap the screen. A simple restart usually fixes this.
Would like to know if anyone has solved/repaired any similar problems with their flip.