Touch disease or not?

My iPhone 6 + screen is not responding, if I left it for 2 days there is a chance it works again but after 5hours it ain't working anymore.

I think it's the touch disease but I don't see a grey flickering bar at the top of my screen.

Can someone confirm it's the touch disease or it's something else?

I already replaced the screen by a new one but it's the same problem.

Thanks in advance.