OpenCart 4.0.2.3 with PayPal 3.2.2
User fills out out Guest Checkout - clicks continue - Clicks Choose then PayPal for method. Clicks continue for Payment.
PayPal opens popup window, User selects PayPal or Credit.
Credit is Selected, Name, Zip, email, PH then Pay is clicked.
Form resets and no success page is returned. Order is captured in OpenCart and Payal, plus email is sent.
If user completes again, then Success page is returned. Order is not duplicated.