I am here because I have problems with PayPal SandBox and WooCommerce:
I already configured everything (API KEY of the SandBox) but when doing the proof of payment it works but it does not return to the site and the order is not put as "Processing", it appears as "Pending payment".
I am using WAMP for testing on a domain like my-domain.com-dev without HTTPS.
Any solution?
If you are using WooCommerce's old standard HTML-only PayPal integration, it depends on IPN delivery for payment confirmations. IPN delivery requires a publicly-accessible webserver reachable via HTTPS (details)
As an alternative, there is a newer WooCommerce PayPal module with Smart Payment Buttons that you can try instead: https://woocommerce.com/woocommerce-and-paypal/ -- this may not depend on the IPN service.