Server Island fails when using i18 and prefixDefaultLocale set to true

[nima-hakimi]

Astro Info

Astro                    v5.1.1
Node                     v22.5.1
System                   macOS (arm64)
Package Manager          npm
Output                   server
Adapter                  @astrojs/node

If this issue only occurs in one browser, which browser is a problem?

Describe the Bug

Fetching the Server Island fails when using i18 and prefixDefaultLocale set to true. It fails with 404 when I use the following file structure: src/pages/[locale]/index.astro

What's the expected result?

The expected result would be to fetch the Server Island correctly.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-fmzsdm7p-mklde2ku?file=astro.config.mjs

Participation

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