Custom Domain Redirect to Edge Function Returns 404 - Works on .supabase.co but not on Custom Domain

[valueunlimited007]

Custom Domain Redirect to Edge Function Returns 404

Problem Summary

I have a critical SEO issue where /sitemap.xml returns 404 on my custom domain fiskar.se, but the same Edge Function works perfectly when accessed directly via the Supabase URL.

Supabase Plan: Pro
Project ID: jbfxcpqqcjisgbsapeed
Custom Domain: fiskar.se (verified and working for other routes)

Current Setup

Edge Function

• Function name: sitemap
• Direct URL: https://jbfxcpqqcjisgbsapeed.supabase.co/functions/v1/sitemap
• Status: ✅ Works perfectly - returns XML sitemap with correct content-type: application/xml

Config.toml Redirect

[[redirects]]
from = "/sitemap.xml"
to = "/functions/v1/sitemap"
status = 200

Problem

• Custom domain URL: https://fiskar.se/sitemap.xml
• Status: ❌ Returns 404 Not Found
• Expected: Same XML sitemap as direct Edge Function URL

Testing Results

Working (Direct Edge Function):

curl -I https://jbfxcpqqcjisgbsapeed.supabase.co/functions/v1/sitemap
# Returns: HTTP/1.1 200 OK, content-type: application/xml

Not Working (Custom Domain):

curl -I https://fiskar.se/sitemap.xml
# Returns: HTTP/1.1 404 Not Found

Troubleshooting Steps Taken

1. ✅ Verified Edge Function is deployed and working
2. ✅ Confirmed no static sitemap.xml file exists in project root
3. ✅ Verified no conflicting redirects in config.toml
4. ✅ Confirmed custom domain works for all other routes
5. ✅ Tried multiple redeployments with code changes
6. ✅ Tested in incognito/private browsing
7. ✅ Waited over 24 hours for potential propagation

Questions

1. Does anyone have a working setup with an edge function on /sitemap.xml for a custom domain (NOT .supabase.co)?
2. Are there additional steps needed for custom domains to handle Edge Function redirects?
3. Is there a known issue with config.toml redirects not applying to custom domains?
4. Could this be related to DNS/proxy layers that handle custom domains differently?

Impact

This is blocking Google Search Console sitemap submission and affecting SEO indexing for our production site.

Additional Info

• Support ticket submitted: (will update with ticket number)
• Custom domain SSL working correctly
• All other routes on custom domain work fine
• No issues with the React app routing

Has anyone experienced similar issues with custom domain redirects to Edge Functions? Any workarounds or solutions would be greatly appreciated!

[GaryAustin1]

Where have you seen it documented you can move functions from https://fiskar.se/functions/v1/sitemap.xml ?

Is there a document on [[redirects]] you are using?

I can't find anything on this.