Hi,
You can change the effective date using an Odoo server action. You also need to update the date
fields of the related stock moves and stock move lines to match the
effective date. Only then will the stock be reflected as processed on
the backdated date(2023).
1. Settings->Technical->Actions->Server Actions
Type: Execute Code
Model: Transfer

2. Run
the server action on the receipt corresponding to the purchase order by
going to Purchase Order -> Receipt ->Action -> Stock Move in
Backdate.

After running the server action, you will see that the effective date has been changed to the backdated value.

Stock Move

Stock Move Line

Hope it helps