A Playwright script can look stable until a proxy enters the workflow. Without a proxy, the page opens. The selector works. The click happens. The test passes. Then you add a proxy. Suddenly the page hangs. Authentication fails. Login behaves differently. A request times out. The same script works in visible mode but fails in headless mode . A retry succeeds once and fails again five minutes later. The first reaction is usually simple: The proxy is bad. Sometimes that is true. But a Playwright proxy failure is not always a proxy failure. It can be a browser context , proxy authentication , profile state , region mismatch , or retry-boundary problem. If you debug all of those as “proxy not working,” you will waste time changing IPs while the real issue stays hidden.…