If a note is associated with a product and the "Auto display" box is checked, then the note will be displayed when a line is inserted in a sales document (quote, order, delivery or invoice).
When an order is created from a quote, a delivery is created from an order or an invoice is created from a delivery, the note is no longer displayed automatically.
It would be useful to create a parameter to allow the product notes to be re-displayed when a sales document is created from the higher-level document