Magento 233 upgrade to 248p3: Shipstation Auctane_Api not working on Payment step of Checkout Page

Checkout page issue with Shipstation Shipping Method:

When I reach the checkout page and complete the details during the Shipping step, the system loads the available shipping rates loaded from Shipstation Shipping Method and selects a shipping method. After clicking the Next button, I proceed to the payment step. However, I am experiencing an issue with the selected shipping method.

In the Order Summary, the shipping method does not appear and is shown
as follows:

Shipping 
Selected shipping method is not available. Please select another shipping method for this order.

I need to return to the Shipping step to select the shipping method again. When I get back to the Shipping step, I notice that the shipping method I previously selected is no longer checked.

After I select the shipping method again, I click the Next button to proceed to the payment step. The name of the selected shipping method appears in the Order Summary section, along with the shipping rate that was displayed during the Shipping step, for example, $5.40. However, after a second, the shipping rate changes to $0, and the Order Total only reflects the Cart Subtotal amount, excluding the shipping fee.

Current shipping data in the Order Summary after the post-load:

Shipping
Shipping - Standard Delivery, max 4 estimated transit days, 5 - 10 days
$0.00

I am experiencing an issue with the shipping method in the order summary. Although the shipping rates are displayed during the shipping step, the order summary shows the shipping method with a rate of $0. When I select a payment method, enter the required payment details, and click the “Place Order” button, I receive the following error message:

"The shipping method is missing. Select the shipping method and try again."

As a result, I am unable to complete my order from my upgraded store.

The shipping method I am using is ShipStation (Auctane_Api).

Errors in log Files:

  1. var/log/shipping.log
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
  1. var/log/debug.log
main.CRITICAL: Placing an Order failed (reason: The shipping method is missing. Select the shipping method and try again.) {"quote_id":"bgcL7yCFrAhDddcBsocUfcw0BxH3JpM5","exception":"Magento\Framework\Validator\Exception: The shipping method is missing. Select the shipping method and try again. in vendor/magento/module-quote/Model/QuoteValidator.php:109
  1. var/log/system.log
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
main.ERROR: [SHIPSTATION] From: AuctaneApiModelCarrierShipping [] []
main.ERROR: [SHIPSTATION] Message: Infinite loop detected, review the trace for the looping path [] []
  1. var/log/exception.log
main.CRITICAL: Placing an Order failed (reason: The shipping method is missing. Select the shipping method and try again.) {"quote_id":"bgcL7yCFrAhDddcBsocUfcw0BxH3JpM5","exception":"Magento\Framework\Validator\Exception: The shipping method is missing. Select the shipping method and try again. in vendor/magento/module-quote/Model/QuoteValidator.php:109

Additional notes:

  • The default Shipping Methods like Flat Rate, Free Shipping, Table
    Rates are working fine. The selected default shipping method’s name
    and rates are appearing under the Order Summary section and I’m able
    to place the Orders successfully.
  • Only issue appears when trying to
    place order using Shipstation Shipping Method.

I see the these information in the Network tab during the payment step when I select the Shipstation shipping method.

  • Shipstation shipping issue of amount 0 on payment step: shipping_amount 5.58, shipping_discount_amount 0, shipping_incl_tax 5.58, shipping_tax_amount 0
  • SHIPSTATION From AuctaneApiModelCarrierShipping Message Infinite loop detected, review the trace for the looping path.

Any help would greatly appreciated. Thanks is advance! 🙂