Object spawning in wrong place and changes to 'Is kinematic' and 'use gravity' not affecting object (VR)

I'm creating a snowball fight game for the HTC Vive. When the controller is placed into a snow pile a snowball should be spawned in the same position as the controller - this is held whilst the trigger is held. When the trigger is released the snowball should be thrown/dropped (depending on the movement of the controller).

However, the snowball spawns a few feet away from the controllers position (still affected by the movement of the controller as it should be). Also, when the trigger is released it should be thrown/affected by gravity however instead just stays in the same place as when the trigger was released... The snowball's rigidbody does change to use gravity = true and isKinematic = false though. Can anyone help with either issue pleeeeeease?

Here's the code:

     public class ThrowSnowball : MonoBehaviour {
  
     private Valve.VR.EVRButtonId triggerButton = Valve.VR.EVRButtonId.k_EButton_SteamVR_Trigger;
     private SteamVR_TrackedObject trackedObj;
     private SteamVR_Controller.Device device;
     public GameObject Snowball;
     Rigidbody sbrb;
     private GameObject collided;
     private bool sb = false;
     private GameObject Spawning;
     public Transform controller;
 
     void Awake()
     {
         trackedObj = GetComponent<SteamVR_TrackedObject>();
         sb = false;
         Debug.Log("sb = false");
 
     }
 
     private void OnTriggerEnter(Collider collider)
     {
         Debug.Log("Entered snow pile");
 
         collided = collider.gameObject;
          
         }
     private void OnTriggerExit(Collider other)
     {
         Debug.Log("Exited snow pile");
         collided = null;
     }
 
     private void Update()
     {    
         device = SteamVR_Controller.Input((int)trackedObj.index);
 
         if (sb == false && device.GetPressDown(triggerButton) && collided != null)
         {
             Debug.Log("Trigger Pressed");
 
             Spawning = Instantiate(Snowball, transform) as GameObject;
             sbrb = Snowball.GetComponent<Rigidbody>();
             sbrb.isKinematic = true;
             sbrb.useGravity = false;
             Spawning.gameObject.transform.SetParent(transform);
             sb = true;
             Debug.Log("sb = true");
         }
 
         if (device.GetPressUp(triggerButton) && sb == true)
         {
             Debug.Log("Let go of trigger");
             sbrb.isKinematic = false;
             sbrb.useGravity = true;
             Spawning.gameObject.transform.SetParent(null);
             sb = false;
             Debug.Log("sb = false");
             ThrowSB(sbrb);
         }
     }
     void ThrowSB(Rigidbody sbrb) {
         Transform origin = trackedObj.origin ? trackedObj.origin : trackedObj.transform.parent;
             sbrb.velocity = device.velocity;
         sbrb.angularVelocity = device.angularVelocity;
     }
 }