We have now sorted out some of the checkout issues but there is still an error related to payments on the product pages as you can see in this image.
https://prnt.sc/pC9w4W1AnGQ7
As we had this error on both our websites, we have entered code at your suggestion to remove it on the other website, but Woocommerce Payments say this is an element related to the Express Checkout buttons that are missing and it has been reduced to a 1px line (which you can see just before the – OR -. They recommended we get in touch with the theme developers and let them know it’s not working as intended.