Duplicate contribution created for recurring payments in Stripe v6.9.1

If a user makes a recurring payment with Stripe two contributions are created. The first contribution has status Completed and is as expected. But there is a second contribution that has status Pending for the same amount and at the same time. The ID of the pending contribution is higher so was presumably created later.

We have come across this issue on three separate sites running different versions of CiviCRM (5.62.1 and 5.63.1).

Our testing indicates that this is an issue for both existing contacts and new contacts. It affects both logged in and logged out users. It's an issue for both monthly and annual payments. I've tested with and without a confirmation page.

Both sites were previously on the Stripe extension 6.8.2 and this issue wasn't present.

Environment:

• Stripe extension versions: 6.7.14, 6.9.1 and 6.9.3
• CiviCRM versions: 5.62.1, 5.63.1 and 5.64.4
• Drupal 7.98 / WordPress 6.2.2
• PHP 8.1 (also tested in PHP 8.0 and 7.4)

One site is in production the other two are test sites with the contribution pages in test drive mode.