Astro Info

Astro                    v6.0.4
Node                     v25.8.1
System                   macOS (arm64)
Package Manager          pnpm
Output                   static
Adapter                  @astrojs/cloudflare
Integrations             @astrojs/solid-js

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

All.

Describe the Bug

In the preview environment, UI framework (Solid.js and React are tested) component inside a server island (server:defer) is not rendered, an empty response is returned from the server, without any kind of error message.

However, in the dev environment this is working correctly.

This happens when setting prerenderEnvironment to node and workerd (default).

What's the expected result?

Response from server island should include the UI framework component

Link to Minimal Reproducible Example

https://github.com/CaiJimmy/astro-v6-break-cf-prerender

Participation

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