PayPal Checkout cannot be completed when Cloudflare Turnstile is enabled

[dwanjuki]

Describe the bug
When Cloudflare Turnstile is enabled, it is not possible to complete the checkout via PayPal Express.

Users are required to confirm the payment on site after returning from PayPal. This happens even when Skip the extra confirmation after users return from PayPal is selected in the Payment Gateway settings.

After returning from PayPal, the following error is displayed on the checkout page: Please complete the security check.

When the Complete Payment button is clicked, the following error is displayed: The response parameter (token) has already been validated before. This means that the token was issued five minutes ago and is no longer valid, or it was already redeemed.

To Reproduce
Steps to reproduce the behavior:

1. Enable the PayPal Express gateway.
2. Checkout for a membership level, pay via PayPal Express
3. See errors.

Screenshots

Expected behavior
The extra confirmation step is not required if it's disabled in the Payment Gateway settings.
Checkout is successful.

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only Paid Memberships Pro plugin is active.
• This bug happens with a default WordPress theme active, or Memberlite.
• I can reproduce this bug consistently using the steps above.

WordPress Environment
WP 6.7.1
PMPro 3.3.2