Socket hang up with ExpressJS

[Huynh_Nam]

Hi all,
I've setup my server with elastic-apm-node, and it run ok. But after a period of time (30-60 min), it causes an error like below:

Error: socket hang up
    at createHangUpError (_http_client.js:331:15)
    at Socket.socketOnEnd (_http_client.js:423:23)
    at emitNone (events.js:111:20)
    at Socket.emit (events.js:208:7)
    at endReadableNT (_stream_readable.js:1055:12)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)

This error made my server down too, so I need to restart it. After removed the code, everthing okay now.
This is my config code:

require('elastic-apm-node').start({
  serviceName: '...',
  secretToken: '...',
  instrument: true,
  captureBody: 'all',
  errorOnAbortedRequests: true,
  serverUrl: 'http://...:8200',
  active: process.env.NODE_ENV === 'production'
})

Version

Elasticsearch, Kibana, APM v6.2.1
NodeJS v8.9.4
ExpressJS v4.15.2

I searched for this error, but there's no results with apm-server. Is this a known issue, or my configuration miss something? Please help me to fix this.
Thanks!