Curently there is no solution to fix this issue, beside change the hardware,
I've tried to restore and upgrade the iOS, but it seems the problem is not the software issue, it was the hardware issue (the screen),
So i bring
the iphone to the apple store, they said the problem were in the screen, not the software,
They suggest so to replacing the screen.
Lucky for me it still warranty,
So they change the iphone,
Have you tried to restore the ios?
Because if you don't fix it fast, it will buggy when you type or pointing your fingger on the screen, and could spread all the screen,
I hope this could help you,