Duplicate shipping charges at checkout, no payment method

Hi, I am lost... in the shopping cart, the product costs and shipping costs are displayed correctly. However, during the checkout process, the shipping costs are added again, resulting in them being charged twice.
Additionally, in the cart it is not possible to select a payment method. The payment options only appear after clicking the “Order” button once. Then an error message appears saying “Please select a payment method,” and only then does the payment selection field become visible.

We are currently reviewing the reported issue by following up on the support ticket that was raised regarding this matter. Kindly refer to the ticket for further updates.Thank you