Well it happen no matter I have cloned screen or not. Currently I calibrate EyeX again and it is slightly better but not perfect.
It clearly visible, you I look close to corners, tracking loose precision.
Below you can see calibration test (after fresh calibration): https://www.youtube.com/watch?v=gW4SmtFYy6Y&feature=youtu.be
As you can see I have problems with reaching top regions of screen especially top right corner.