Galaxy A7 2018 navigation buttons not working

[Members_6EXOcRY]

The Navigation Buttons at the bottom of the screen are not working. In general everything else is working although occasionally touch on any part of the screen fails and restart is required. Can anyone suggest what might be causing this problem?

[xSteveuk]

Hi,
Try a diagnostic test
Click on the get help button
At the bottom of the samsung members page
Touch Screen

[Members_6EXOcRY]

Yes I tried that and can fill whole screen with green squares. Unfortunately the diagnostic does not check the navigation button area. I notice that when the screen has a black background and navigation buttons are white, the buttons light up brighter for about 2 secs when touched which suggests that touch is detected in that area.