Facing issue with Drag and Drop in UI

Getting Started
,
1

So I am creating a Inventory system where I am trying to implement drag and drop functionality from my shop to my inventory slots, the dragging part is working fine but I am not able to drop my item on my inventory slots, i am using IDrophandler for the drop functionality and the weird part is that OnDrop function itself is not getting called properly for some reason, it’s getting called randomly (1 out of 5 times).

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class DragableItem : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
{
    [SerializeField]
    Image iconImage;
    [SerializeField]
    private Transform parentAfterDrag;

    private Canvas canvas;
    private ItemDisplay itemDisplay;
    private RectTransform rectTransform;
    [SerializeField]
    private InventorySlot inventorySlot;
    private RectTransform startPosition;
    private bool checkForItemSlotEmpty;
    private Vector2 pos;

    //ToDo : The item should be dropabel in inventory slot

   // Setter
    public void SetParentTransform(Transform transform)
    {
        parentAfterDrag = transform;
    }

    public void SetInventorySlot(InventorySlot inventorySlot)
    {
        this.inventorySlot = inventorySlot;
    }

    private void Awake()
    {
        canvas = GetComponentInParent<Canvas>();
        rectTransform = GetComponent<RectTransform>();
        itemDisplay = GetComponentInParent<ItemDisplay>();
        startPosition = rectTransform;
        pos = startPosition.anchoredPosition;
    }
    private void Update()
    {
        checkForItemSlotEmpty = itemDisplay.IsItemSOEmpty();
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        //Debug.Log(" isItemSoEmpty : " + itemDisplay.IsItemSOEmpty() + " of item display " + itemDisplay);
        if (checkForItemSlotEmpty == true)
            return;

            iconImage.raycastTarget = false;
            parentAfterDrag = transform.parent;
            transform.SetParent(transform.root);
            transform.SetAsLastSibling();
    }

    public void OnDrag(PointerEventData eventData)
    {
        if (checkForItemSlotEmpty == true)
            return;
        itemDisplay.SetCanShowDiscWindow(false);
        transform.position = Input.mousePosition;
        //rectTransform.anchoredPosition += eventData.delta / canvas.scaleFactor;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        if (checkForItemSlotEmpty == true)
            return;

        //inventorySlot = eventData.pointerDrag.GetComponent<InventorySlot>();
        transform.SetParent(parentAfterDrag);
        itemDisplay.SetCanShowDiscWindow(true);
        iconImage.raycastTarget = true;
        Debug.Log("Parent after drag is : " + parentAfterDrag);
        //if (inventorySlot == null)
        //{
        //    Debug.LogError("InventorySlot empty");
        //    rectTransform.anchoredPosition = pos;
        //}
        ////// Check if the drop location is over a new item slot
        ////if (eventData.pointerEnter != null && inventorySlot !=null)
        ////{
        ////    transform.SetParent(eventData.pointerEnter.transform);
        ////}
        //else
        //{
        //    transform.SetParent(inventorySlot.transform);
        //}
    }

}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class InventorySlot : MonoBehaviour,IPointerEnterHandler, IDropHandler
{
    [SerializeField]
    DragableItem dragableItem;
    public void OnDrop(PointerEventData eventData)
    {
        Debug.Log("OnDrop called");
        GameObject dropped = eventData.pointerDrag;
        if (dropped == null)
        {
            Debug.Log("No item was being dragged.");
            return;
        }

        Debug.Log("Dropped object: " + dropped.name);

        dragableItem = dropped.GetComponent<DragableItem>();
        if (dragableItem == null)
        {
            Debug.Log("Dropped object is not a draggable item.");
            return;
        }

        dragableItem.SetParentTransform(transform);
        Debug.Log("Dropping item into slot: " + dropped.name);
    }
    public void OnPointerEnter(PointerEventData eventData)
    {

        //Debug.Log("Inside Inventory Slot");
        //GameObject dropped = eventData.pointerDrag;
        //dragableItem = dropped.GetComponent<DragableItem>();
        //dragableItem.SetInventorySlot(this);
    }
}