why nodejs cannot close tcp connection？

Question

this is my client.js code

const http = require('http')
const axios = require('axios')

http.globalAgent.keepAlive = true
http.globalAgent.maxFreeSockets = 700

const test = async () => {
  const ret = await axios.post('http://localhost:9000/test')
  console.log('============ret', ret)
  for (let i = 0; i < 10000000; i++) {
    console.log(i)
  }
}

test()

this is my server.js code.

const express = require('express')
const http = require('http')

// set globalAgent
http.globalAgent.keepAlive = true
http.globalAgent.maxFreeSockets = 700

const PORT = 9000
const app = express()

app.post('/test', (req, res, next) => {
  res.send('hello')
})

// start server
const server = app.listen(PORT)

server.keepAliveTimeout = 60 * 1000

this is package.json，rely on [email protected] [email protected]

{
  "dependencies": {
    "axios": "^0.26.1",
    "express": "^4.17.3"
  }
}

nodejs version v16.13.0

Wireshark version 3.6.3

my expected is

// 2022-04-08 update

the clinic analyse result