Children Not Moving With Parent From Instantiation?

can you please be more clear about your question? ps: make sure you don't have a rigid-body attached to your gameobject or else it will be under control of physics and won't move with parent.

You're moving only one child that is just created, why do you expect other children to be moved?

Sort of something weird I found. This problem occurs only if I instantiate the child and its respective children at run time.

If I add the object child and its children to the hierarchy in the inspector and run the same program with a reference to the child rather than the Instantiated object the child and respective children all move uniformly as expected.

Here are some photos of my process and the direct code.

In this photo above I placed FullDeck as a child of Game before running the program, when the following code ran the results were as expected where just the coordinates of FullDeck were changed and none of its children cards moved

     public GameObject fullDeckRef;
     public GameObject emptyDeckRef;
     public GameObject fullDeck;
     // Start is called before the first frame update
     void Start()
     {
         float xOffset = 1f;
         float yOffset = 3.111111f / 2f+1;
         Vector3 cameraPoint = Camera.main.ScreenToWorldPoint(new Vector3(Screen.width, Screen.height, 10));
         Debug.Log(cameraPoint);
         cameraPoint.x -= xOffset;
         cameraPoint.y -= yOffset;
         fullDeck.transform.position = cameraPoint;
     }

I then got rid of FullDeck and changed the code to have the following two lines which instantiates the FullDeck and its children from the reference.

     public GameObject fullDeckRef;
     public GameObject emptyDeckRef;
     public GameObject fullDeck;
     // Start is called before the first frame update
     void Start()
     {
         float xOffset = 1f;
         float yOffset = 3.111111f / 2f+1;
         fullDeck = Instantiate(fullDeckRef, new Vector3(0, 0, 0), Quaternion.identity);
         fullDeck.transform.parent = transform;
         Vector3 cameraPoint = Camera.main.ScreenToWorldPoint(new Vector3(Screen.width, Screen.height, 10));
         Debug.Log(cameraPoint);
         cameraPoint.x -= xOffset;
         cameraPoint.y -= yOffset;
         fullDeck.transform.position = cameraPoint;
     }

This then produced the following result

In this instance FullDeck is at the same position, 8.0, 3.4, but in this second case all of the FullDeck's children have been set to position -8.0,-3.4