Paypal cannot receive payment

This app used to work perfectly for our website (thank you so much!) until we tried to link the donate button to another Paypal account, and then we received this error message: “Sorry, we weren’t able to complete your payment at this time. Please try again later. If you continue to encounter problems, please contact customer service.”

To go into detail, the donate button on this page is still linked to the old Paypal account and is working perfectly: https://www.helpingelephants.org/donations/

But the donate button on this page is linked to the new account and payment does not go through: https://www.helpingelephants.org/carbon-offset/

I suspect that this is a problem on the plugin becasue the new Paypal account can still accept donations made directly through Paypal

The page I need help with: [log in to see the link]