I am experiencing a persistent 502 Bad Gateway error on all preflight OPTIONS requests to my Node.js/Express service, which is preventing my front-end application from functioning.

Evidence:

1. My service is stable and healthy. The deployment logs confirm that the application starts successfully, connects to the database, and responds to the /health check path as expected.

   • Deployment Log:

     [INFO] Application starting...
     [INFO] Database pool created successfully.
     [INFO] Server is running on http://0.0.0.0:8080
     

2. The error only occurs on preflight OPTIONS requests from the browser. The attached HTTP log shows the OPTIONS request to /auth/login failing with a 502 status after a 10-second timeout.

   • HTTP Log Snippet:

     method: "OPTIONS"
     path: "/auth/login"
     httpStatus: 502
     totalDuration: 10575
     

3. The request never reaches my application. My application code includes detailed logging for all incoming requests, and the OPTIONS request from the browser never appears in the deployment logs.

This evidence strongly indicates that the issue is with the Railway proxy/gateway layer, which is not correctly forwarding these specific preflight requests to my running container.

Why is the proxy is returning a 502 error for these requests instead of routing them to my healthy service?