Get Kinect v2 2d joint position

Hi, I'm trying to get 2d joint position of Kinect v2 detected body.
I'd like to have a game object overlaying an avatar joint only in 2d.

By looking at examples and online, I can get the screen joint position in this way:

Code (CSharp):

1. Vector3 posJoint = manager.GetJointPosColorOverlay(userId, iJointIndex, foregroundCamera, backgroundRect);

But the issue is when I try to apply this position onto an overlay object.

I get a "parallax" effect like the object is at another z.