Investigate possible conflict with PayPal Payments

[jorgeatorres]

When the PayPal Checkout Gateway plugin is active (the gateway can be disabled, but plugin needs to be active), then a second "Place order" button may appear in the checkout.
The second button can be triggered by clicking the PCP gateway name or the radio button when it was already selected.
For some merchants, the PayPal Card Processing always displayed the second button.
We figured that there seem to be other potential causes that could make the "Place order" button appear, (because not all reporters had the Checkout plugin installed) but this is one method to consistently trigger the behavior.

Related:
woocommerce/woocommerce-paypal-payments#176

[AlexP11223]

It happens because this plugin updates the button visibility on click instead of change + with some delay caused by animation.

https://github.com/woocommerce/woocommerce-gateway-paypal-express-checkout/blob/trunk/assets/js/wc-gateway-ppec-order-review.js

But it should not be a problem after woocommerce/woocommerce-paypal-payments#361