Full Answer

Most WooCommerce tracking plugins work by injecting JavaScript on the order confirmation page. The script reads the order details from the dataLayer and fires a purchase event to GA4, Google Ads, Meta, or whichever platform is configured. This depends on one assumption: the customer actually reaches that page with the script intact.

PayPal breaks that assumption. The customer leaves your domain, completes payment on paypal.com, and PayPal redirects them back. If the redirect fails — a mobile connection drops, the customer closes the browser, PayPal's return URL times out, or a pop-up blocker interferes — the confirmation page never loads and the tracking script never fires. The same pattern applies to Stripe 3D Secure, Klarna, Afterpay, and any gateway that sends the browser off-site. The sale is real, the money arrived, but your analytics platforms have [no record of it](https://mdniamul.com/blog/ga4-woocommerce-tracking-fix-missing-purchases/).

The fix is architectural: move the purchase event trigger from the browser to the server. When tracking fires from WooCommerce's payment_complete hook — a server-side event triggered by the payment gateway's webhook confirming the charge — the customer's browser path becomes irrelevant. Whether they returned to the confirmation page, closed the tab, or lost connectivity, the event fires because the server received the payment confirmation directly. That is the structural difference between [client-dependent and server-driven tracking](https://seresa.io/blog/server-side-tracking/five-signs-your-woocommerce-tracking-is-broken-and-you-dont-know-it).