Network / firewall ?

failed on teardown with "firebird.driver.types.DatabaseError: Unable to complete network request to host "localhost".
-Failed to establish a connection."

LOG DETAILS:

2025-07-13 15:59:32.898
2025-07-13 15:59:32.898 act = <firebird.qa.plugin.Action object at [hex]>
2025-07-13 15:59:32.898
2025-07-13 15:59:32.898     @pytest.mark.version('>=3.0')
2025-07-13 15:59:32.898     def test_1(act: Action):
2025-07-13 15:59:32.898         script = f"""
2025-07-13 15:59:32.898             create database '{act.db.dsn}' user '{act.db.user}'
2025-07-13 15:59:32.899               password '{act.db.password}' set names 'win1251' default character set utf8 ;
2025-07-13 15:59:32.899             set list on ;
2025-07-13 15:59:32.899             select c.rdb$character_set_name as client_char_set, r.rdb$character_set_name as db_char_set
2025-07-13 15:59:32.899             from mon$attachments a join rdb$character_sets c on a.mon$character_set_id = c.rdb$character_set_id
2025-07-13 15:59:32.899             cross join rdb$database r
2025-07-13 15:59:32.899             where a.mon$attachment_id = current_connection ;
2025-07-13 15:59:32.899         """
2025-07-13 15:59:32.899         act.expected_stdout = expected_stdout
2025-07-13 15:59:32.899         act.isql(switches = ['-q'], input=script, connect_db=False, combine_output = True)
2025-07-13 15:59:32.899 >       assert act.clean_stdout == act.clean_expected_stdout
2025-07-13 15:59:32.899 E       assert
2025-07-13 15:59:32.899 E         - CLIENT_CHAR_SET                 WIN1251
2025-07-13 15:59:32.899 E         - DB_CHAR_SET                     UTF8
2025-07-13 15:59:32.899 E         + Statement failed, SQLSTATE = 08006
2025-07-13 15:59:32.899 E         + Unable to complete network request to host "localhost".
2025-07-13 15:59:32.899 E         + -Failed to establish a connection.
2025-07-13 15:59:32.899
2025-07-13 15:59:32.899 tests\functional\database\create\test_01.py:38: AssertionError