Narrowing a checkout failure to the payment step

Test checkout only as far as it is safe to do so. Record whether the cart, shipping details, payment selection, and final confirmation each load. Do not repeatedly submit a purchase while unsure whether an order was created.

If the failure begins after choosing a payment method, note the method type without sharing card or account details. Check order history before retrying, and compare another device or browser only if that will not create a duplicate charge.

At which exact step does checkout stop?