Sony offers official statement on Xperia stripe display issues15
Unfortunately, the same issue seems to affect some Xperia XZ2 units as well, though the number of people who experience the stripe display issue is currently unknown. Many haven't reported the issue since the stripes disappear from the display if you tap on the screen several times.
The folks over at Tweakers received an official statement from Sony that confirms the issue, but the Japanese company says this isn't a manufacturing defect but the result of … static electricity.
Xperia XZ1 and XZ2 units. If you live in a cold and dry place, chances are that your phone won't be affected by static electricity.Basically, the issue appears due to warm and humid places, so if it will not affect all