Payments on my store are intermittently failing at the PayPal checkout stage—customers see an error after clicking “Pay Now” and the order never records in the system. Everything else on the site runs smoothly, so the issue is isolated to the payment flow. I need a developer who understands the PayPal REST API, IPN/webhooks and typical WooCommerce-style (PHP) integrations to: • trace where the transaction breaks, • restore reliable authorisation and capture, and • test live and sandbox modes to confirm stability. Please be comfortable working on a live e-commerce environment, backing up before touching core files or gateway settings, and providing a concise summary of what was fixed so I can maintain it going forward.