I tested the Vuforia hololens sample with Unity 2017.2.0f3 and Vuforia 6.5.25 (downloaded on the Unity Asset Store).
I have some offsets about the virtual target position, the virtual target is about 2-3 centimeters in front of the physical target with the hololens.
I disabled the extended tracking to visualize the target without the hololens tracking.
The offsets are not reduced without extended tracking.
The size of my printed target is the same as the size in the vuforia database and on the ImageTarget object.
Moreover, I tested the same sample with a logitech camera C920, the virtual target is perfectly aligned on the physical target.
Please find attached a comparative sample of hololens and logitech camera.
Would you have any idea to fix these offsets?