APM Metrics not shown in Kibana APM App

[behnood (Behnood1)]

Kibana version: 7.9.2

Elasticsearch version: 7.9.2

APM Server version: 7.9.2

APM Agent language and version: elastic-apm-node 3.7.0

Browser version: Chrome 85

Fresh install or upgraded from other version? Fresh Install on Ubuntu 18.04

Description of the problem including expected versus actual behavior. Please include screenshots (if relevant):

Hello everyone. I have a freshly installed Elasticsearch/Kibana/APM stack and everythings works great. APM Server processes data sent by my Nodejs app and Kibana APM Dashboard shows the data.

Here is the problem after a few hours, data in Metrics tab of Kibana APM Dashboard stop showing. When I look at apm-7.9.2-metric-000001 Doc count in Index Management I can see that the data is being received by APM Server and apm metric's doc count is growing but Kibana APM Dashboard tells me there is no metric data to show.

If I restart my nodejs app, the metrics data start showing in Kibana APM Dashboard again but only for a few hours and it stops again.

Here is my apm agent config:

const apm = require('elastic-apm-node')
  apm.addFilter(function (payload) {
    if (payload.context.request && payload.context.request.headers) {
      payload.context.request.headers['cookie'] = '[REDACTED]'
    }
    if (payload.context.response && payload.context.response.headers) {
      payload.context.response.headers['set-cookie'] = '[REDACTED]'
    }
    return payload
  })
  apm.start({
    serverUrl: Config.apmServerAddress,
    active: true,
    captureBody: 'errors',
    centralConfig: false,
    asyncHooks: true,
    metricsInterval: '30s',
  })

Any suggestions as to what is happening here?