Dell latitude 5285 touch screen issue - Bottom of screen can't be touched

I got replacement of LCD module on Oct, 2018. Because the bottom screen didn't respond. After replacement, It had not been happened until the early of May, 2019. But it happened again around 2 weeks ago. I found some articles about the bottom screen touch issue by googling. Even some users who encountered such issue got replacement of LCD module, they reported it happened again after their replacement. So, it could be easily guessed that another root cause would exist besides the faulty LCD module. I think dell should figure out clear root cause of it. And it would be necessary to provide clear solution for this issue including FOC replacement for the products what are out of warranty .