Question (SteamVR) Motion controllers don't behave as should on model rig

Hi all, I followed a 'How to make a body' tutorial for my VR game but it doesn't seem to work properly with SteamVR/The Knuckle controllers/Skeleton with inversed kinematics.

What happens:
1) The arms don't move at the right speed so you need to move more in order to get the arm moved just a little bit
2) The hand does move left / right if you move the controller left/right but when you move the controller up the hand goes down (and the other way around, controller down hand goes up)

I recorded a video so the text above is easier to understand (https://i.imgur.com/MrBKnv9.mp4)

The script I use to make the hands/head rotate:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. [System.Serializable]
6. public class VRMap
7. {
8.     public Transform vrTarget;
9.     public Transform rigTarget;
10.     public Vector3 trackingPositionOffset;
11.     public Vector3 trackingRotationOffset;
12.  
13.     public void Map()
14.     {
15.         rigTarget.position = vrTarget.TransformPoint(trackingPositionOffset);
16.         rigTarget.rotation = vrTarget.rotation * Quaternion.Euler(trackingRotationOffset);
17.     }
18. }
19.  
20. public class VRRig : MonoBehaviour
21. {
22.     public VRMap head;
23.     public VRMap leftHand;
24.     public VRMap rightHand;
25.  
26.     public Transform headConstraint;
27.     public Vector3 headBodyOffset;
28.  
29.     // Start is called before the first frame update
30.     void Start()
31.     {
32.         headBodyOffset = transform.position - headConstraint.position;
33.         //headBodyOffset = new Vector3(0, 0, 0);
34.     }
35.  
36.     // Update is called once per frame
37.     void Update()
38.     {
39.         transform.position = headConstraint.position + headBodyOffset;
40.         transform.forward = Vector3.ProjectOnPlane(headConstraint.up, Vector3.up).normalized;
41.  
42.         head.Map();
43.         leftHand.Map();
44.         rightHand.Map();
45.     }
46. }
47.  

Is there any solution for this?