I shipped a static Astro site to Cloudflare Pages this week. Build was green, every local check passed, the custom domain resolved. Three things were still broken, and all three were platform defaults I never touched.

None of them throw an error. That is the whole problem.

1. Cloudflare rewrites your robots.txt

My repo has a four-line robots.txt. Allow everything, point at the sitemap. Here is what the live site actually served:

# BEGIN Cloudflare Managed content