Hi,

I am trying to connect a custom domain to my Railway frontend service (HTML/CSS/JS static site).

My setup:

• Frontend deployed on Railway
• Custom domain: itlearningbh.com
• DNS managed via Cloudflare
• CNAME records correctly pointing to Railway domain
• Both root and www domains are configured

However, I am facing issues:

1. The domain sometimes returns "502 Bad Gateway"
2. Sometimes I get "Application failed to respond"
3. SSL certificate issues appear for www subdomain (ERR_CERT_COMMON_NAME_INVALID)
4. I have already set Cloudflare DNS to "DNS only" (not proxied)
5. My app runs a static server using serve and listens on process.env.PORT

I have verified:

• DNS records are correct
• Railway deployment is active
• Application runs successfully on Railway default domain

But the custom domain is not stable and does not properly resolve.

Could you please help me verify the correct setup for:

• Custom domain configuration on Railway for a static frontend
• Proper handling of www + root domain
• SSL certificate provisioning for custom domain

Thank you.