Paypal Smart Buttons plugin not working in NopCommerce 4.4

I am also having issues with Paypal smart buttons, i have had this reply from paypal

Thank you for contacting PayPal Merchant Technical Support.
I understand that you are not able to receive payment from your website.

After reviewing your checkout the Smart Payment Button shortcut is not working, so it needs to be removed.

The next thing that is happening is that the redirect url (where the buyer gets sent after PayPal) is not going to the confirmation page. It is instead going back to the Payment page with the smart payment button. There is supposed to be a Next button on the page or the buyer is supposed to be redirected to the Confirmation page.



Your web developer needs to work with your shopping cart to fix the redirect page to go to the confirmation page. Most likely there is a theme or a setting that is stopping the redirection to the confirmation page.

It looks like you may be using NopCommerce as your shopping cart provider, so your web developer needs to work with NopCommerce to determine why the buyer is not getting directed to the confirmation page.

https://www.mahilaartskadi.org/Content/Images/Result/44.pdf

According to their Guide there is supposed to be a Next Button that pops up to send the buyer to the Confirmation Page. Either the Next is not showing, which could be a theme issue, or the buyer is not being redirected to the correct page.

I apologize for the inconvenience this issue has caused.
Thank you for using PayPal and have a wonderful day!

Could it be related to this problem? (was this problem also in 4.40?)

https://www.nopcommerce.com/en/boards/topic/93066/one-page-checkout-not-working-when-order-totals-on-payment-info-tab-option-is-enabled-nop-version-45

If you have selected Order Setting "Order totals on payment info tab", then try unselecting it.

We'll check this, thanks for the details. Here is a work item.

I am getting the same issue with the paypal commerce plugin. Did changing the setting paymentsettings.regenerateorderguidinterval to a higher value help?

I am not sure of the point of changing the GUID. I have set it to 10 minutes but am reluctant to set it too high as I don't understand why the guid need changing in the first place.