Database still in use after a selenium test in Django

I have a Django project in which I'm starting to write Selenium tests. The first one looking like this:

from django.contrib.staticfiles.testing import StaticLiveServerTestCase
from selenium import webdriver
from selenium.webdriver.common.keys import Keys

from core.models import User
from example import settings

BACH_EMAIL = "johann.sebastian.bach@classics.com"
PASSWORD = "password"


class TestImportCRMData(StaticLiveServerTestCase):
    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        cls.webdriver = webdriver.Chrome()
        cls.webdriver.implicitly_wait(10)

    @classmethod
    def tearDownClass(cls):
        cls.webdriver.close()
        cls.webdriver.quit()
        super().tearDownClass()

    def setUp(self):
        self.admin = User.objects.create_superuser(email=BACH_EMAIL, password=PASSWORD)

    def test_admin_tool(self):
        self.webdriver.get(f"http://{settings.ADMIN_HOST}:{self.server_thread.port}/admin")

        self.webdriver.find_element_by_id("id_username").send_keys(BACH_EMAIL)
        self.webdriver.find_element_by_id("id_password").send_keys(PASSWORD)
        self.webdriver.find_element_by_id("id_password").send_keys(Keys.RETURN)
        self.webdriver.find_element_by_link_text("Users").click()

When I run it, the test pass but still ends with this error:

Traceback (most recent call last):
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
psycopg2.OperationalError: database "test_example" is being accessed by other users
DETAIL:  There is 1 other session using the database.


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 168, in <module>
    utility.execute()
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 142, in execute
    _create_command().run_from_argv(self.argv)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\commands\test.py", line 26, in run_from_argv
    super().run_from_argv(argv)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\base.py", line 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\core\management\base.py", line 353, in execute
    output = self.handle(*args, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_manage.py", line 104, in handle
    failures = TestRunner(test_labels, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_runner.py", line 255, in run_tests
    extra_tests=extra_tests, **options)
  File "C:\Program Files\JetBrains\PyCharm 2018.2.4\helpers\pycharm\django_test_runner.py", line 156, in run_tests
    return super(DjangoTeamcityTestRunner, self).run_tests(test_labels, extra_tests, **kwargs)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\runner.py", line 607, in run_tests
    self.teardown_databases(old_config)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\runner.py", line 580, in teardown_databases
    keepdb=self.keepdb,
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\test\utils.py", line 297, in teardown_databases
    connection.creation.destroy_test_db(old_name, verbosity, keepdb)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\base\creation.py", line 257, in destroy_test_db
    self._destroy_test_db(test_database_name, verbosity)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\base\creation.py", line 274, in _destroy_test_db
    % self.connection.ops.quote_name(test_database_name))
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\pupeno\Documents\Eligible\code\example\venv\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
django.db.utils.OperationalError: database "test_example" is being accessed by other users
DETAIL:  There is 1 other session using the database.

The problem of course is that the next run of the tests, the database still exists, so, the tests don't run without confirming deletion of the database.

If I comment out the last line:

self.webdriver.find_element_by_link_text("Users").click()

then I don't get this error. I guess just because the database connection is not established.

I've been trying to find the minimum reproducible example of this problem, but so far I haven't succeeded.

Any ideas what could be causing this or how to find out more about what the issue could be?