I am creating a membership invoice, with a float quantity for  a certain purpose

I am trying to pass a float value as quantity  to invoice line..when it passes the the price_subtotal is not updating properly. Instead the price_unit changes to round the price_subtotal....The code here

@api.model_create_multi
def create(self, vals_list):
    lines = super(AccountMoveLine, self).create(vals_list)
    print('create value lines', lines)
    print('create value list', vals_list)
    # product = self.env['product.product'].browse(
    #     vals.get('product_id', False)
    # )
    to_process = lines.filtered(lambda line: line.move_id.type == 'out_invoice'
                and line.product_id.membership and line.product_id.membership_prorate)



    invoice_line_vals = []
    for line in to_process:
        if line.product_id.membership_prorate:
            line_vals = self._prepare_invoice_line_prorate_vals(
                line)
            print('line_vals prorate', line_vals)
        if line_vals:
            date_from = line_vals.pop('date_from')
            for vals in vals_list :
                # val['quantity'] = line_vals['quantity']
                # if val['move_id']

                # val.update({"quantity": line_vals['quantity']})
                                                       vals.update(line_vals)###########################IMPORTANT##########

                currency =                                self.env['res.currency'].browse(
                                                                               vals.get'cuency_id'))                                                            
                partner =                 self.env['res.partner'].browse(vals.get('partner_id'))
                taxes = self.resolve_2many_commands('tax_ids',                     vals.get('tax_ids', []), fields=['id'])
                tax_ids = set(tax['id'] for tax in taxes)
                taxes = self.env['account.tax'].browse(tax_ids)

                move =                     self.env['account.move'].browse(vals['move_id'])
                vals.update(self._get_price_total_and_subtotal_model(
                    vals.get('price_unit'),
                    vals.get('quantity'),
                                    vals.get('discount', 0.0),
                    currency,
                                        self.env['product.product'].browse(                                        vals.get('product_id')),
                    partner,
                    taxes,
                    move.type,
                ))


                                move.with_context(
                check_move_validity=False)._recompute_dynamic_lines\                                                
                    (recompute_all_taxes=True)

                # line.write(vals)

            self.quantity = line_vals['quantity']


            # invoice_line_vals.append(line_vals)
            # date_from = invoice_line_vals['date_from']

            # line.write(invoice_line_vals)#was there
            print('vals_list[0]',vals_list[0])
            line.write(vals_list[0])#updated there
           
 



    return lines

Eg: The unit price is 1 and the quantity is 0.86, but it recalculate as below




This is the vals_list updated
for lines = super(AccountMoveLine, self).create(vals_list)

create value list 2 [{'date': datetime.date(2020, 7, 21), 'journal_id': 1, 'company_id': 1, 'company_currency_id': 2, 'account_id': 19, 'name': 'Test Product', 'quantity': 0.85, 'price_unit': 1.0, 'discount': 0.0, 'debit': 0.0, 'credit': 1.0, 'balance': -1.0, 'amount_currency': 0.0, 'price_subtotal': 0.85, 'price_total': 0.85, 'currency_id': False, 'partner_id': 44, 'product_id': 78, 'payment_id': False, 'tax_ids': [(6, 0, [])], 'tax_repartition_line_id': False, 'tag_ids': [(6, 0, [])], 'matched_debit_ids': [(6, 0, [])], 'matched_credit_ids': [(6, 0, [])], 'analytic_line_ids': [(6, 0, [])], 'recompute_tax_line': False, 'display_type': False, 'is_rounding_line': False, 'exclude_from_invoice_tab': False, 'always_set_currency_id': 2, 'sale_line_ids': [(6, 0, [])], 'move_id': 113, 'tax_exigible': True}, {'company_id': 1, 'company_currency_id': 2, 'account_id': 6, 'name': '', 'quantity': 0.85, 'price_unit': -1.0, 'discount': 0.0, 'debit': 1.0, 'credit': 0.0, 'balance': 1.0, 'amount_currency': 0.0, 'price_subtotal': -0.85, 'price_total': -0.85, 'date_maturity': datetime.date(2020, 7, 21), 'currency_id': False, 'partner_id': 44, 'product_id': False, 'tax_ids': [(6, 0, [])], 'exclude_from_invoice_tab': True, 'always_set_currency_id': 2, 'sale_line_ids': [(6, 0, [])], 'move_id': 113, 'tax_exigible': True}]