Hello,

1. Could you please check how it works with some default WordPress themes like TwentyTwenty or WooCommerce Storefront to understand is it our theme issue or not?

2. If you are in a hurry, you can define the below code that will help you to fix that, in Theme Settings -> Custom CSS.

.wcpay-payment-request-wrapper {
	padding-top: 0 !important;
}

form.cart .wcpay-payment-request-wrapper {
    order: 25;
}

Kind Regards