The details do not establish the exact cause, but I would check the public routing first. Make sure the public domain is attached to the Wekan service (not MongoDB), and that its target port matches the port Wekan actually listens on. Railway routes a public domain to the service’s configured internal target port. Its troubleshooting guidance recommends that the web process bind to 0.0.0.0 and listen on Railway’s injected PORT, so PORT=3000 is only correct if this template’s Wekan entrypoint actually listens on 3000. Otherwise, align the app’s listening port and the domain target port. If it still returns 502, please share the Wekan startup log showing the bound host/port and the Networking target-port setting, with secrets redacted. Docs: https://docs.railway.com/networking/domains/working-with-domains#target-ports and https://docs.railway.com/networking/troubleshooting/application-failed-to-respond#application-not-listening-on-the-correct-host-or-port