missing to_uom when process sale that has not uom, but user add uom in invoice line

Scenario:

1. Create a Sale:

• Set the invoice method to "From Order."
• Add a line without selecting a product, specifying only the quantity and unit price. Process the Sale:

2. Confirm and process the sale: an invoice draft is created.
3. Edit the Invoice Line:

• Add a unit of measure (UoM) to the line and save the changes.

4. Process the sale again:

Traceback (most recent call last):
  File "/tryton/trytond/trytond/worker.py", line 144, in run_task
    task.run()
  File "/tryton/trytond/trytond/ir/queue_.py", line 177, in run
    getattr(Model, self.data['method'])(
  File "/tryton/trytond/trytond/model/modelview.py", line 720, in wrapper
    return func(cls, records, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/sale/sale.py", line 1049, in process
    cls._process_invoice(sales)
  File "/tryton/trytond/trytond/modules/sale_invoice_grouping/sale.py", line 62, in _process_invoice
    super()._process_invoice([sale])
  File "/tryton/trytond/trytond/modules/sale/sale.py", line 1061, in _process_invoice
    invoice = sale.create_invoice()
              ^^^^^^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/sale_invoice_line_standalone/sale.py", line 39, in create_invoice
    invoice_lines.extend(line.get_invoice_line())
                         ^^^^^^^^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/sale_invoice_line_standalone/sale.py", line 87, in get_invoice_line
    invoice_lines = super(SaleLine, self).get_invoice_line()
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/sale/sale.py", line 1710, in get_invoice_line
    - self._get_invoiced_quantity())
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/sale/sale.py", line 1784, in _get_invoiced_quantity
    quantity += Uom.compute_qty(
                ^^^^^^^^^^^^^^^^
  File "/tryton/trytond/trytond/modules/product/uom.py", line 200, in compute_qty
    raise ValueError("missing to_uom")
ValueError: missing to_uom