View Inventory Item Record in History tab and it shows duplicate item fulfillment number

 
1.  Open the Item Fulfillment
2.  Check all the items from the list except the inventory item that is in question (e.g. Item A)
3.  If there is a kit item which is part of the item fulfillment, check if one of the members of the kit is the item in question (e.g. Item A)
 
If yes, then that is the answer which is the reason why item fulfillment on history tab of the item record shows duplicate item fulfillment number because it is recognizing the decrease in item quantity and cost of the item as an inventory item and also that inventory item as part of a kit item.