Railway support ticket — custom domain stuck at edge fallback 404 (cert VALID, syncStatus ACTIVE)

Project: webgen (id 2cbee5f5-05b7-41fd-9aa9-b0cc1a9cae35), env production

Service: webgen-web (id 4c799d10-4828-4c74-933b-eb0598d7f9d9) — a Next.js app, listens on port 8080

Custom domain: webgen.emiko.io

Summary

A custom domain will not route to its service. Railway's control plane reports the

domain healthy — syncStatus: ACTIVE, certificateStatus: VALID, correct

serviceId/environmentId, targetPort: 8080 — and the TLS cert is correctly issued

for webgen.emiko.io (Let's Encrypt). But every request to https://webgen.emiko.io

returns a Railway edge fallback 404:

HTTP/2 404
server: railway-hikari
x-railway-fallback: true
x-railway-edge: waw1
{"status":"error","code":404,"message":"Application not found"}

The service is healthy and its railway.app domain works perfectly:

https://webgen-web-production.up.railway.app/ → HTTP 200.

What we've verified / ruled out

• DNS: CNAME webgen.emiko.io → <target>.up.railway.app, propagated on both authoritative

  nameservers and public resolvers; Railway API shows currentValue == requiredValue,

  DNS_RECORD_STATUS_PROPAGATED.

• Cert: customDomainIssueCertificate → CERTIFICATE_STATUS_TYPE_VALID; edge presents

  a valid CN=webgen.emiko.io Let's Encrypt cert.

• targetPort: explicitly set to 8080 (the app's listening port) at domain creation.

• Service binding: correct serviceId + environmentId per the API.

• Tried: redeploying the service; deleting and recreating the custom domain from

  scratch (twice — got fresh targets and fresh edge nodes each time: 69.46.46.42,

  then 69.46.46.30). The fallback 404 persists across both edges.

• No CAA records, no DNSSEC, port 80 reaches the edge (HTTP 301 → https).

• The DNS record's currentValue reported by your API is unstable: it flaps

  between the correct requiredValue (e8fy5h7k.up.railway.app) and the target of a

  PREVIOUSLY DELETED registration (9j5lwtix.up.railway.app) on repeated polls —

  suggesting a stale/inconsistent internal DNS cache.

• Critically: even at the moments when currentValue == requiredValue

  (status PROPAGATED, cert VALID, syncStatus ACTIVE), the edge STILL returns the

  fallback 404. So DNS-match is not the gating factor — the route simply never

  reaches the edge.

• customDomainUpdate (re-set targetPort) and customDomainIssueCertificate both

  return success and do not change the outcome.

Ask

The edge is not picking up the route for this custom domain despite the control plane

reporting it ACTIVE/VALID. Please flush/re-sync the edge routing for

webgen.emiko.io on service webgen-web, or advise what's preventing the route from

propagating to the edge.

We've reverted DNS to our previous host to keep the site up in the meantime, and will

re-point to Railway once the edge routing is fixed.