I am using Xperia Z3 dual (D6633). I also have the same problem since the last update 23.5.A.1.291 2 days ago. I have been using my Sony Xperia Z3 D6633 for almost 1.5 years and face no MAJOR problem until the last update (Except low speaker volume after lolipop and current marshmallow update).
My phone dont have any hairline cracks and I havent dropped not even once.
First the dropdown notification doesnt work properly before last update and also back key area of touch screen was not responding well. It was also failing in diagnostics touchscreen test.
Then, after a new current update the home, back and recent button is not working as well. It is not working. Buttons are not working on portrait mode but works on landscape mode. I believe its not the touch screen that have issues, 'cause when in lock screen the voice assist button, lock icon and camera button where the home, back and opion button are located worked.
These 3 buttons works good in Landscap mode.
I have tried all things like service menu check, factory reset and last software repair. Today I took it to Service centre but Sony staff has no solution of these. They told me to root phone (which I am not going to Do).
I really hope someone could help us on this. A lot of z3 users have same issues. Without these 3 buttons the phone is basically useless, unless you're fine with restarting your phone everytime you finish using an app. Im still hoping for the update to fix this. SONY PLS GIVE THE FINAL SOLUTION.
