Unable to run FunctionalJavascriptTests

[mstrelan]

Describe the bug

When running FunctionalJavascriptTests with a default setup I see the following error:

1) Drupal\FunctionalJavascriptTests\Ajax\AjaxCallbacksTest::testDateAjaxCallback
WebDriver\Exception\UnknownError: unable to set cookie
  (Session info: headless chrome=74.0.3729.157)
  (Driver info: chromedriver=2.38.552522 (437e6fbedfa8762dec75e2c5b3ddb86763dc9dcb),platform=Linux 5.4.0-1051-gke x86_64)

To Reproduce

• Spin up DrupalPod from the link on the Github project
• Run the following commands:

composer require --dev phpspec/prophecy-phpunit:^2
ddev phpunit core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php

Expected behavior

Tests pass like below:

Testing Drupal\FunctionalJavascriptTests\Ajax\AjaxCallbacksTest
..                                                                  2 / 2 (100%)

Time: 00:08.473, Memory: 4.00 MB

OK (2 tests, 8 assertions)

Additional context

I was able to reproduce the error in a local ddev setup using the same docker-compose.testing.yaml that was found in DrupalPod. After changing SIMPLETEST_BASE_URL: http://localhost to SIMPLETEST_BASE_URL: $DDEV_PRIMARY_URL and removing the same env vars from .ddev/commands/web/phpunit the tests pass, but I don't get the same result in DrupalPod.