Custom domain edge/TLS issue — inconsistent behavior across Vercel edge IPs while *.vercel.app works

Help
1

Hi Vercel team — I’m seeing what looks like a custom-domain edge/TLS/routing issue on a Hobby project.

Summary

  • My project’s native *.vercel.app deployment works normally
  • The custom apex domain and www subdomain are both attached to the correct project
  • In the Vercel dashboard, both show:
  • Valid Configuration
  • Production
  • But the branded/custom domain path is inconsistent depending on the edge path

What I verified

  • The Vercel deployment itself is healthy because the *.vercel.app hostname works
  • The custom domains are bound to the right project in Vercel
  • DNS is pointing to Vercel targets using external DNS
  • I already tried the recommended workaround:
  • removed both custom domains
  • waited
  • re-added them
  • confirmed they reassigned to production
  • The issue still persists after re-adding

Debug findings
I ran the Vercel connectivity debug script, and the results were inconsistent across the resolved Vercel edge IPs for the custom domain:

  • one edge IP:

  • completes TLS successfully

  • presents the correct certificate for the custom domain

  • but then the HTTP request hangs / times out with 0 bytes returned

  • the other tested Vercel edge IPs:

  • reset during TLS handshake (connection reset by peer)

So this does not look like:

  • an app/runtime problem
  • a simple DNS typo
  • or a stale local DNS cache issue

It looks more like:

  • inconsistent custom-domain edge behavior
  • or an issue in TLS/routing/certificate state across edge nodes

Why I’m posting
Because:

  • *.vercel.app works
  • custom domain config shows valid
  • remove/re-add did not fix it
  • edge behavior appears inconsistent across Vercel-served IPs

Has anyone seen this before, or can a Vercel team member help review the edge/certificate/routing state for a custom domain showing this pattern?

I have the full vercel-debug.txt output and can share it privately with Vercel staff if needed.

If a team member wants the full debug output, please reply here and I can provide it directly.

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