diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index e5f286cabc..c758504fb9 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -6,6 +6,7 @@
  */
 
 use Drupal\Component\Utility\UrlHelper;
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\DrupalKernel;
 use Drupal\Core\Database\Database;
 use Drupal\Core\Database\DatabaseExceptionWrapper;
@@ -156,6 +157,7 @@ function install_drupal($class_loader, $settings = []) {
       install_display_output($output, $state);
     }
     elseif ($state['installation_finished']) {
+      Cache::getBins()['config']->delete('last_write_timestamp_cache_config');
       // Redirect to the newly installed site.
       install_goto('');
     }
diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index 09a7aad57c..f2970f4b56 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -143,6 +143,12 @@
 
 $test_list = simpletest_script_get_test_list();
 
+if (in_array('Drupal\FunctionalTests\Installer\DistributionProfileExistingSettingsTest', $test_list)) {
+  $test_list = array_fill(0, 20, 'Drupal\FunctionalTests\Installer\DistributionProfileExistingSettingsTest');
+} else {
+  $test_list = [];
+}
+
 // Try to allocate unlimited time to run the tests.
 drupal_set_time_limit(0);
 simpletest_script_reporter_init();
diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index e7c79f380a..36efc40e6b 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -571,6 +571,10 @@ public function assertSession($name = NULL) {
   protected function prepareRequest() {
     $session = $this->getSession();
     $session->setCookie('SIMPLETEST_USER_AGENT', drupal_generate_test_ua($this->databasePrefix));
+    $cookies = $this->extractCookiesFromRequest(\Drupal::request());
+    if (isset($cookies['XDEBUG_SESSION'])) {
+      $session->setCookie('XDEBUG_SESSION', current($cookies['XDEBUG_SESSION']));
+    }
   }
 
   /**