Transforming the position of a placed GameObject - unity3d

Question

I'm trying to move a cube from A to B. The app I'm working on uses Unity / ARKit to detect a plane. On a touch event it places a cube. This currently works as anticipated.
I now want to transform placed cube to a new position, however my cube is stationary. In the code below, I place the cube. Then, in that if statement, I call a method called MoveToB, which should get the GameObject called objectToPlace and transform it's position. I assume this is where the code is going wrong.
void Update()
{
UpdatePlacementPose();
UpdatePlacementIndicator();
if (placementPoseIsValid && Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began) {
PlaceObject();
Debug.Log("Object Placed"); // This gets called
MoveToB();
}
}
private void MoveToB()
{
objectToPlace.transform.position = new Vector3(100, 100, 100);
Debug.Log("MoveToB Triggered"); // This gets called
}
Is anyone able to point me in the right direction?
Rest of the code...
private void PlaceObject()
{
Instantiate(objectToPlace, placementPose.position, placementPose.rotation);
}
private void UpdatePlacementIndicator()
{
if (placementPoseIsValid) {
placementIndicator.SetActive(true);
placementIndicator.transform.SetPositionAndRotation(placementPose.position, placementPose.rotation);
} else {
placementIndicator.SetActive(false);
}
}
private void UpdatePlacementPose()
{
var screenCentre = Camera.current.ViewportToScreenPoint(new Vector3(0.5f, 0.5f));
var hits = new List<ARRaycastHit>();
arOrigin.Raycast(screenCentre, hits, TrackableType.Planes);
placementPoseIsValid = hits.Count > 0;
if (placementPoseIsValid) {
placementPose = hits[0].pose;
var cameraForward = Camera.current.transform.forward;
var cameraBearing = new Vector3(cameraForward.x, 0, cameraForward.z).normalized;
placementPose.rotation = Quaternion.LookRotation(cameraBearing);
}
}

Answer 1

objectToPlace seems to be a prefab?
If that's teue than
objectToPlace.transform.position = new Vector3(100, 100, 100);
tries to translate that prefab, not the object (clone) you Instantiated in your scene.
Instead you should store the reference of placed object
private GameObject spawnedObject;
private void PlaceObject()
{
spawnedObject = Instantiate(objectToPlace, placementPose.position, placementPose.rotation);
}
And than move it
private void MoveToB()
{
spawnedObject.transform.position = new Vector3(100, 100, 100);
Debug.Log("MoveToB Triggered"); // This gets called
}