What version of astro are you using?

2.9.0

Are you using an SSR adapter? If so, which one?

Vercel

What package manager are you using?

pnpm

What operating system are you using?

Mac, Windows

What browser are you using?

Chrome, Firefox, Safari

Describe the Bug

Deployed app: https://astro-vercel-404-edge-bug.vercel.app/
Code: https://stackblitz.com/edit/github-z7x12r?file=src%2Fpages%2F404.astro

Astro website deployed on Vercel using edge adapter doesn't recognize 404.astro page and browser native 404 page is shown instead.

It works in development, it doesn't work on Vercel only. It doesn't matter whether the 404.astro is prerendered or not.

What's the expected result?

Navigating to a page that doesn't exist shows the content of 404.astro.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-z7x12r?file=src%2Fpages%2F404.astro

Participation

• I am willing to submit a pull request for this issue.