I have a 7 inch touchscreen which has been working fine over the last few years but recently it has a dead zone across the centre (full width, landscape orientation). It works fine at the top 25% and the bottom 40% approximately.
I have checked the connections and they all seem OK - any suggestions please to get it to work properly over the whole screen?
I first noticed it using PiCorePlayer but have also confirmed the symptoms using Raspbian latest version. Presumably it is a hardware problem?