A static page can return the correct HTML and still display the wrong content once JavaScript runs. On a small AI-assisted website, an index.html alias exposed exactly that failure: the server supplied an interior page, then client-side route selection replaced it with the homepage. The useful fix was to align route identity across the host and the browser, while keeping unknown paths unknown.

The response was correct. The rendered page was not

The failing address was /formation/index.html. It pointed to a real generated HTML file. Looking only at its HTTP response suggested that the route worked. After the client script ran, however, the page showed the homepage.

This was not evidence that static hosting was unreliable. Two parts of the application interpreted the same address differently. The host understood a file path, while the browser-side code selected content from a route map whose keys used directory-style URLs.

That distinction changes the debugging question.…