Brightness level stuck at minimum after upgrading to Android 5.1.1 I have Sony Xperia Z (C6603, 10.7.A.0.222) and the brightness level is stuck at minimum after update to 5.1.1. 

I have tried:


sensor test - light sensor is OK.
set brightness via ADB (settings put system screen_brightness 200) - didn't work.
using brightness control apps (like LUX for example) - didn't work. 


Using stock ROM without root, any apps or functions that could set brightness to low for saving battery are either uninstalled or turned off? Any suggestions?
This happened to me on my galaxy note20 3 weeks ago.  My screen went pretty dark.  After a hour or so i saw on settings blue light filter was on.  I did not turn it on. I had to shut it off then reset the phone.