Hello, I own an Xperia X F5121 and so far very happy with it.
Only thing to complain is that I get an dark display area on my display that won't disappear.
So far I tested this things:
Start Device in Safe mode
Device repair option in Xperia Companion
Update to Android Oreo
Reset to Factory settings
Screen test in Support app
Problem is also in Android Nougat
In all tests the dark area was visible.
Any help here?