In Odoo 17 purchase.order has invoices:

invoice_ids = fields.Many2many('account.move', compute="_compute_invoice", string='Bills', copy=False, store=True)

and each account.move has a purchase:

purchase_id = fields.Many2one('purchase.order', store=False, readonly=False,
    string='Purchase Order',
    help="Auto-complete from a past purchase order.")

I added a simple field in Purchase:

class PurchaseOrder(models.Model):
    _inherit = "purchase.order"
    accounting_note = fields.Char()

and want to show this field's value in each related Invoice, too:

class AccountMove(models.Model):
    _inherit = "account.move"
    accounting_note = fields.Char(readonly=True)

So far I tried to compute it in AccountMove, but failed:

accounting_note = fields.Char(compute="_compute_accounting_note")

@api.depends("purchase_id")
def _compute_accounting_note(self):
    for record in self:
        record.accounting_note = record.purchase_id.accounting_note

and to set it onchange in PurchaseOrder (write is not allowed here, according to docs), but failed too:

@api.onchange("accounting_note")
def _update_accounting_notes(self):
    for record in self:
        for invoice in record.invoice_ids:
            invoice.accounting_note = record.accounting_note

In Purchase Order the value is fine, but it never appeared in the Invoices.
I suppose this due to certain limitations of the store/computed M2M/O2M fields.
How do I get this right?