Dynamically-created cube with mouse follow script does not follow mouse

The goal of this script is that the object it's attached to should move with the mouse.

public sealed class FollowMouseComponent : MonoBehaviour
    {
        private InputHandler _inputHandler;
        private InputAction _touch;
        private InputAction _mouse;
        private static Plane _plane = new(Vector3.up, Vector3.zero);
        
        private Ray _ray;
        private RaycastHit _raycastHit;
        private bool _isDragging;
        public void EndDragging() => _isDragging = false;
        
        public Camera Camera { get; set; }

        private IEnumerator Start()
        {
            _inputHandler = FindObjectOfType<InputHandler>();
            Camera = Camera.main;
            
            while (!_inputHandler.Ready)
            {
                yield return null;
            }

            _touch = _inputHandler.Control.Touch;
            _mouse = _inputHandler.Control.Mouse;
            _isDragging = true;
        }

        private void Update()
        {
            if(_isDragging)
            {
                HandleInput();
            } 
            else
            {
                Release();
            }
        }        

        private void HandleInput()
        {
            var mousePosition = Mouse.current.position.ReadValue();
            Debug.LogFormat("{0}: Mouse position: {1}", gameObject.name, mousePosition);
            _ray = Camera.ScreenPointToRay(mousePosition);
            if (!_plane.Raycast(_ray, out float distance))
            {
                return;
            }
            gameObject.transform.position = _ray.GetPoint(distance);
            Debug.LogFormat("{0}: {1}", gameObject.name, gameObject.transform.position);
        }
        
        private void Release()
        {
            if (!CanRelease())
            {
                return;
            }
            Debug.LogFormat("Releasing");
            Destroy(this);
        }

        private bool CanRelease()
        {
            Debug.LogFormat("Touch is pressed: {0}, Mouse is pressed: {1}", _touch.IsPressed(), _mouse.IsPressed());
            return !_touch.IsPressed() || !_mouse.IsPressed();
        }
    }

I have a cube in the scene with this script. This cube behaves as expected. However, if I create a cube using another script and assign this script to it as a component, the created cube does not follow the mouse.

Here's the code I use to spawn the cube:

var gameObject = GameObject.CreatePrimitive(PrimitiveType.Cube);
gameObject.AddComponent<FollowMouseComponent>(); 

What could be the reason this script-created cube does not follow the mouse?