We using the standard Magento 2 PayPal integration.

On the production site of our customer, we get an Javascript error "window.paypal.ThreeDomainSecure is not a function", and payment cannot continue.

This happens when trying to place an order with the inline VISA form on the Checkout (not when using an existing paypal account).

We cannot find this line of code in the Magento code, so we believe the error comes from the components loaded from PayPal

Did anybody see this issue before and knows a solution or how to narrow it down?

Is it likely to be related to the PayPal account or a technical issue?