I have the following problem:

I would like to produce product A (traced by Serial Number).
Product A needs 5 units of product B (BOM).
Product B is traced by Lots.
I have 20 units of product B on hand (Lot X 10 units, Lot Y 10 units).

I create a manufacturing order for 4 units of product A.
The overall consumption is 20 units of product B.
The detailed operation shows reservations of 10 units of Lot X and 10 units of Lot Y - all correct.

If I click on "Mass Produce" Odoo raises the following error message:

Component Lots must be unique for mass production. Please review the consumption for: Product B 

I would assume that Odoo creates the following backorders:

2 products A with Lot X of product B
2 products A with Lot Y of product B

I don't understand why Odoo raises this error instead of creating these backorders?

What's the Odoo way of handling this use case?