You build a WordPress form. It should save without reloading the page.
You click Send. Nothing happens.
Or the Network tab shows admin-ajax.php returning a single character: 0.
If that sounds familiar, you are not alone. After six years of building WordPress themes, plugins, and WooCommerce projects, I keep seeing the same pattern on client sites. The JavaScript looks fine. The PHP looks fine. But the request never reaches the callback — or it reaches the wrong hook — or the response is not JSON at all.
Most of the time, the problem is not JavaScript skill. It is not understanding how WordPress routes background requests.
