The first thing, Czech support and all who make up for it are probably on vacation, even sitting behind a table at work.
Problem with the problem and proposal for solution I mentioned several times Czech support. In a nutshell :
Add the xperia settings:
1) when the camera is on, or at least in the background
2) setting, automatic shutdown of the camera
3) setting, automatic saving of the display brightness value according to the rider setting to ambient light
