We're sorry for the trouble. We're aware of an issue affecting DNS resolution and are working on it. Follow updates at https://status.railway.com/incident/cmlv7yk1o0169a8bl7vvvqwir

Sorry - on closer review the DNS warning you're seeing is expected when using Cloudflare with proxy enabled (orange cloud). Cloudflare masks the underlying CNAME target behind their own IPs, so Railway can't verify the record directly. As long as your CNAME is pointed at the correct target, traffic will route properly.

A couple things to check:

Cloudflare SSL/TLS mode: Make sure this is set to Full (not "Flexible" and not "Full (Strict)"). Flexible will cause redirect loops or connection errors, and Full Strict can fail because Railway's edge certificate won't match Cloudflare's strict validation.

Calling the CNAME target directly: Hitting 0s9xqbvo.up.railway.app in your browser will always return a 404. That hostname is only a routing target for your CNAME, not a service domain you can browse to directly. Your requests should go through your custom domain api.vivenda.io).

Some endpoints not waking serverless: When your service is asleep, the first request wakes it up. During the cold start, your Express app may not be ready to handle all routes immediately. If certain routes (like a health check or a simple JSON endpoint) initialize faster than others, those will respond first while other routes may 404 until the app is fully started. Once the service is awake, all routes should work normally.

If the issue persists after checking the SSL mode, let us know and we can dig deeper.

I'm still receiving the 404 on all of them. Can you check based on the request id ? Here it goes: thKfxnKiS0mb_eZPwoOzXw
Now, after just redeploying the service, everything works as expected

What domains are returning 404 errors?

both custom domains: api.novavivenda.io/status and api.novavivenda.com.br/status were returing 404. Here's a request id for the other domain 3C6R50TPSLKueN1CozsQ6Q

The request ID doesn't help here. Please provide the domains that are returning 404 errors.

Doesn't exist - https://www.nslookup.io/domains/api.novavivenda.io/dns-records/

Loads fine - https://api.novavivenda.com.br/

Unfortunately the error cant be reproduced anymore. I'll create an cron checker and once it fails, I'll come back here. The other domain is api.novavivenda.com.br . Thanks for the quick responses

One more question: Do you know why the warning icon regarded the proxied CNAME ? Doe it always show as warning when proxied ?

What domains have the warning icon?

only the vivenda.io which is managed by cloudflare. Cloudflare SSL/TLS mode was set to Full

That domain doesn't appear to be currently attached to any Railway service.

Is there any missing configuration ?

I got a 404 again at 2026-02-22T04:52:34.278Z
this is the text response {"status":"error","code":404,"message":"Application not found","request_id":"7otV3JAVRmeA_Pflss7a6g"}

Gotcha, we'll be looking into that. We will follow up when we have more information.

Its returning 404 right now. Can you check ?

We will be looking into that. We will follow up when we have more information.

An update: we have resolved the underlying issue that was causing the 404s. You should not see this going forward after a redeploy.