Puppeteer waitForSelector Timeouts After Adding a Proxy

A waitForSelector timeout means the expected element did not satisfy its wait. Adding a proxy before it appeared does not establish that the proxy's TCP connection timed out.

1. Keep the navigation evidence. Record the final URL, main response status and relevant failed requests before the selector wait. In Puppeteer, an HTTP error response is not necessarily thrown as a navigation exception.
2. Inspect the delivered document. Its title or a carefully redacted screenshot can reveal a login challenge, an access-denied page or a different regional page. The intended page may also have failed application requests; check the selector and frame too.
3. Handle any challenge at its source. Configure supported proxy authentication before navigation for a proxy challenge. A destination challenge belongs to the application's authorized workflow, with its own credentials.

This often exposes useful evidence that existed before the element wait became the first exception your code reported. Supplying a website password to the proxy cannot correct that earlier document.

Choose the timer after identifying the failed operation. Navigation, network setup and element waits have different limits. A genuinely slow UI may justify a longer selector wait; an error page will remain the wrong document.

Keep the browser session and route steady while comparing. Changing the proxy, selector and all browser state in one attempt hides which condition mattered.