Internal server error on checkout when selected saved card but then switched to paypal (452)

[AlexP11223]

When customer has a saved card on checkout and select that card as a payment method, but at a last second choose to switch to pay with a PayPal button, he will receive an internal server error message. Merchant will see in the logs an fatal error log file.

CRITICAL Uncaught Error: Call to a member function from_wc_order() on null in /var/www/html/wp-content/plugins/woocommerce-paypal-payments/modules/ppcp-wc-gateway/src/Gateway/ProcessPaymentTrait.php:80

To Reproduce

1. Select a saved card during checkout.
2. Choose PayPal as a payment method instead of the card.
3. See "Internal error" when placing the order.