Checkout end-points not loading since WooCommerce Amazon Pay Gateway PSD2 update

Ever since the latest WooCommerce Amazon Pay Gateway update that includes the Payment Services Directive (PSD2) ability, the checkout on my site no longer returns me to the end-point created in WooCommerce settings. Those settings have not been changed since it last worked.

Also, I’m not sure what has changed with the user authentication that PSD2 implements. I can’t remember entering 2 factor authentication codes with the Google authenticator app during Pay with Amazon login? Can anyone verify this is the PSD2 feature?

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