TypeError: fetch failed
    at Object.fetch (node:internal/deps/undici/undici:11730:11)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async invokeRequest (/app/node_modules/next/dist/server/lib/server-ipc/invoke-request.js:17:12)
    at async invokeRender (/app/node_modules/next/dist/server/lib/router-server.js:254:29)
    at async handleRequest (/app/node_modules/next/dist/server/lib/router-server.js:447:24)
    at async requestHandler (/app/node_modules/next/dist/server/lib/router-server.js:464:13)
    at async Server.<anonymous> (/app/node_modules/next/dist/server/lib/start-server.js:117:13) {
  cause: Error: connect ECONNREFUSED 127.0.0.1:46511
      at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1595:16) {
    errno: -111,
    code: 'ECONNREFUSED',
    syscall: 'connect',
    address: '127.0.0.1',
    port: 46511
  }
}

I'm running next.js 14 on docker on an ubuntu server.
This error is caused when accessing to any api router, and the 500 Internal Server Error Page continues to be displayed.
Strangely, the error did not occur on my windows computer.