I used this z3 compact almost 3 years, and found this problem yesterday. The back button begin to difficult to responds before completely not work only in potrait and counter-clockwise landscape mode.
At first, I thought it was the touch screen problem on bottom left corner. But after I try to clockwise landscape mode, the back button works and found the touch screen on top left corner area (in clockwise landscape) works good.
I also try in Sketch app, and some apps, that the touch screen on bottom left corner area in fullscreen or immersive mode was good.
I hope someone can help me for best solution in this problem soon.
Thanks and sorry for my bad English.
