Why Serialized Packed Items are losing Serial No?

ERPNext
1

I have the given scenario:

I have a Item named “Installation of Router ABC”, that is a product bundle, with the item “Router ABC”

Router ABC is a Serialized Item.

I can make and assign the serial no for the Router, but when I click into “Make Delivery Note” it lose the information of the serialized item, in the “Packet Details”, and ask again for the “Warehouse” and “Serial No” for the “Packed Item”, that was already provided in the “Sales Order”.

2

a workaround using hooks

def on_validate_of_delivery_note(doc, event=None):
  for packet in doc.packed_items:
    if not packet.parent_detail_docname or not doc.get("items", {"name": packet.parent_detail_docname}):
         continue
    item = doc.get("items", {"name": packet.parent_detail_docname})[0]
    packet.warehouse, packet.serial_no = frappe.db.get_value("Packed Item", {"parent": item.against_sales_order or item.against_sales_invoice}, ["warehouse", "serial_no"])