Unable to complete payment! Missing paymentMethodID - contribution page for pledge payments

• Drupal 7.88
• CiviCRM 5.40.2
• Stripe 6.6.2
• MJW Shared 1.0.1

A contribution page for setting up pledge payments, with confirmation page, in test mode. Tested using two basic test card numbers and two regulatory (3d secure) test card numbers from https://stripe.com/docs/testing#regulatory-cards

When initially submitting the form, get the message that it's pre-authorizing the card. The JSON returned from the auth call includes a "payment_method_id" property. During the final submit of the form, get the message "Unable to complete payment! Missing paymentMethodID" and get dumped into /civicrm/admin/contribute?reset=1. Log shows...

Mar 02 21:09:40  [debug] paymentMethodID not found. $params: Civi\Payment\PropertyBag Object
(
    [props:protected] => Array
        (
            [default] => Array
                (
                    [qfKey] => CRMContributeControllerContribution2rdj9v7q5ou8ko08ogo0owwos4s0css0cs88wc48ks4o4ockg8_406
                    [entryURL] => https://redacted.com/civicrm/contribute/transact?reset=1&action=preview&id=120&cid=0
                    [firstName] => Dave
                    [lastName] => Reedy
                    [email-Primary] => redacted
                    [hidden_processor] => 1
                    [payment_processor_id] => 22
                    [select_contact_id] => 26527
                    [priceSetId] => 1537
                    [price_1802] => 4799
                    [is_pledge] => 1
                    [pledge_installments] => 7
                    [pledge_frequency_interval] => 1
                    [pledge_frequency_unit] => week
                    [MAX_FILE_SIZE] => 536870912
                    [ip_address] => redacted
                    [amount] => 7
                    [amount_level] => 7 x weekly payments
                    [currency] => GBP
                    [paymentIntentID] => pi_3KYzPKJO1RCosWLr0XeAm1ja
                    [is_pay_later] => 0
                    [invoiceID] => 27ce31a1ed13702d00449273b76e12c4
                    [is_quick_config] => 1
                    [email] => redacted
                    [description] => test payment page from scratch
                    [isRecur] => 1
                    [auto_renew] => 1
                    [recurFrequencyUnit] => week
                    [recurFrequencyInterval] => 1
                    [recurInstallments] => 7
                    [skipLineItem] => 0
                    [line_item] => Array
                        (
                            [1537] => Array
                                (
                                    [4799] => Array
                                        (
                                            [price_field_id] => 1802
                                            [price_field_value_id] => 4799
                                            [label] => 7 x weekly payments
                                            [field_title] => Payments
                                            [description] => 
                                            [qty] => 1
                                            [unit_price] => 7.000000000
                                            [line_total] => 7
                                            [participant_count] => 0
                                            [max_value] => 
                                            [membership_type_id] => 
                                            [membership_num_terms] => 
                                            [auto_renew] => 
                                            [html_type] => Radio
                                            [financial_type_id] => 9
                                            [tax_amount] => 0
                                            [non_deductible_amount] => 0.00
                                        )

                                )

                        )

                    [financialTypeID] => 9
                    [financial_type_id] => 9
                    [contributionType_name] => Training course fee
                    [financialType_name] => Training course fee
                    [contributionPageID] => 120
                    [contactID] => 26527
                    [payment_instrument_id] => 1
                    [item_name] => Online Payment: test payment page from scratch
                    [contributionID] => 92628
                    [contributionRecurID] => 8618
                    [error_url] => /civicrm/contribute/transact?reset=1&action=preview&id=120&cid=0&_qf_Main_display=1&qfKey=CRMContributeControllerContribution2rdj9v7q5ou8ko08ogo0owwos4s0css0cs88wc48ks4o4ockg8_406
                    [paymentMethodID] => 
                )

        )

    [suppressLegacyWarnings:protected] => 1
    [lastWarning] => 
)

The value shown for paymentIntentID is the same value that was returned in the pre-auth JSON for payment_method_id. Both a contribuiton and recurring contribution that get created are left in a "pending or free trial" status.

Please let me know if you need more information or if there is something you would like me to try. Thanks.