checkoutCompleteWithCreditCardV2 fails with appliedGiftCards

[dstout-current]

I've created a checkout and used checkoutGiftCardsAppend to apply a gift card to it.

I can see in the response that the Checkout says the gift card has been applied: "amountUsedV2":{"amount":"3.53"}

I can see that the payment due has been reduced by the gift card amount: "paymentDueV2":{"amount":"57.79"}

But when I actually call checkoutCompleteWithCreditCardV2, I get this error:

{"code":"TOTAL_PRICE_MISMATCH","field":["payment","amount"],"message":"Amount The amount of the payment must match the total of 61.32."}

61.32 is the total price of the order without the gift card being applied (57.79 + 3.53), but why is this generating an error if the gift card was successfully applied?