Why is my functional test not matching my manual testing? I have a Drupal 8 module for banning users based on country.

In it, I have the following test.

public function setUp() {
  parent::setUp();
  $this-&gt;drupalLogin($this-&gt;adminSitesUser);
}
public function testCompleteBan() {
    // node/1.
    $this-&gt;addBanNode("Read only page");
    // node/2.
    $this-&gt;addBanNode("Complete ban page");
    $this-&gt;drupalGet(IP_BAN_ADMIN_FORM_PATH);
    $edit = array(
      // Set the United States to Read Only
      // 0 = no action / 1 = Read Only / 2 = Complete Ban.
      'ip_ban_US' =&gt; 2,
      // Set the test IP address to a known Google US address.
      'ip_ban_test_ip' =&gt; '66.249.84.22',
      // Configure the paths for read-only and complete ban.
      'ip_ban_readonly_path' =&gt; '/node/1',
      'ip_ban_completeban_path' =&gt; '/node/2',
    );
    $this-&gt;drupalPostForm(IP_BAN_ADMIN_FORM_PATH, $edit, t('Save configuration'));
    $this-&gt;assertOptionSelected('edit-ip-ban-us', 2, 'Complete ban set correctly in country list table.');
    // Should be redirected to complete ban page after logout.
    $this-&gt;drupalGet('user/logout');
    $this-&gt;assertUrl('node/2');
  }


However, I get an error on the last line (assertURL()):
"Expected 'http://d8.dev/node/2' matches current URL (http://d8.dev/). Value 'http://d8.dev/' is equal to value 'http://d8.dev/node/2'."

It seems as if the page is not redirected on logout the way it is when manually testing with an extremely minimal installation and using the exact same settings (including permissions)/workflow as the tests.

Note all the form-based tests are working as well.

Any idea why this is not working in D8? (It works fine in D7.)
The assertion failure looks as though the testing framework isn't following the double redirect (from /user/logout to &lt;front&gt; and thence to /node/2). Maybe explicitly request the front page after logging out?

Ie. 

$this-&gt;drupalGet('user/logout');
$this-&gt;drupalGet('&lt;front&gt;');
$this-&gt;assertUrl('node/2');