Weird behaviour with PointerEventData, UI popup,Weird behaviour with PointerEventData, mirrored position.

Hello. We are creating a game that is basically generated on the canvas. Now I've encountered a problem with our inventory system that is generated with grid layout element. Everything else works, except our pop item description. It's location is mirrored. When I move my mouse to right, it shows the item on the left (on top of the left item). Middle item shows just as it's supposed to.

Should mention that our Canvas is set to "Screen Space - Camera", due to usage of postprocessing stack. And here is the code used on itemdescription:

 public class ItemDescriptionPopUp : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
 {
     //[HideInInspector]
     public Image ItemDescBackground;            // Reference to the popup text background, set in code
     //[HideInInspector]
     public Text ItemDescText;                   // Reference to the popup text, set in code
     public int itemIndex;                       // Reference to the item's switchlist index, set in inspector
     public Image itemIcon;                      // Reference to the item's icon, set in inspector
 
     private Item _item;                         // Current item
 
     // At the start, get the references from the objects.
     void OnEnable()
     {
         ItemDescBackground = gameObject.transform.Find("ItemImageBackground").GetComponent<Image>();
         ItemDescText = gameObject.transform.Find("ItemImageBackground").transform.Find("ItemImageText").GetComponent<Text>();
     }
 
     // When mouse is over the object..
     public void OnPointerEnter(PointerEventData eventData)
     {
         ItemDescBackground.gameObject.SetActive(true);      // Show background
         ItemDescText.gameObject.SetActive(true);            // Show text
     }
 
     // When mouse leaves the object..
     public void OnPointerExit(PointerEventData eventData)
     {
         ItemDescBackground.gameObject.SetActive(false);     // Hide background
         ItemDescText.gameObject.SetActive(false);           // Hide text
     }
 
     // Setup the item's information from the list (only gets the items that are TRUE on gamecontroller's switch list)
     public void Setup(Item currentItem, InventoryPage currentInventory)
     {
         if (currentItem.itemSwitchIndex == 1)
         {
             _item = currentItem;
             ItemDescText.text = "Cigarette count: " + GameController.gameController.cigaretteCount;
             itemIndex = _item.itemSwitchIndex;
             itemIcon.sprite = _item.itemIcon;
         }
         else
         {
             _item = currentItem;
             ItemDescText.text = _item.itemDescText;
             itemIndex = _item.itemSwitchIndex;
             itemIcon.sprite = _item.itemIcon;
         }
     }
 }

Thank you for the help, I've been trying to figure out this for few days now.