Datadog Real User Monitoring breaks node server on IE11

Using the @datadog/browser-rum package from RUM Browser Monitoring, with Node apollo web client fails on IE11.

Seeing multiple requests to https://run-http-intake.logs.datadoghq.com on IE11 that are different than Chrome. Unable to login to the application on IE11. Working theory is that datadogRUM is blocking other application requests on IE11. When datadogRUM is removed, the application is working correctly.

Chrome and IE11 requests:

Request Method: POST RequestURL: https://rum-http-intake.logs.datadoghq.com/v1/input/pub{id}?_dd.application_id={id}&ddsource=browser&&ddtags=sdk_version:1.25.2.env:local&batch_time={timestamp}

Only IE11 request:

Request Method: CONNECT RequestURL: https://rum-http-intake.logs.datadoghq.com Proxy-Connection: Keep-Alive

import { datadogRum } from '@datadog/browser-rum' 

datadogRum.init({
  applicationId: '<DATADOG_APPLICATION_ID>',
  clientToken: '<DATADOG_CLIENT_TOKEN>',
  site: '<DATADOG_SITE>',
  //  service: 'my-web-application',
  //  env: 'production',
  //  version: '1.0.0',
  sampleRate: 100,
  trackInteractions: true,
})

Please let me know what additional information I should find to help with this issue. IE11 issues are no fun. Thank you!

Solution

An issue with IE11 is fixed in v1.26.1 See the fix here: [RUMF-791] prevent IE11 performance entry error #633