low level of logging in python does not work

Question

The question was solved by changing tz = get_localzone() to tz = pytz.utc

I am trying to do logging in Python. I need to swap the local time zone to the New York timezone. class CustomFormatter was developed to do so. When the logging level is INFO or higher, it works fine, but when it's DEBUG it does not work.

import logging
from datetime import datetime
from tzlocal import get_localzone
import pytz

# class CustomFormatter is to change timezone
class CustomFormatter(logging.Formatter):
    def converter(self, timestamp):
        dt = datetime.fromtimestamp(timestamp, tz=get_localzone())
        return dt.astimezone(pytz.timezone('America/New_York'))

    def formatTime(self, record, datefmt=None):
        dt = self.converter(record.created)
        if datefmt:
            s = dt.strftime(datefmt)
        else:
            try:
                s = dt.isoformat(timespec='milliseconds')
            except TypeError:
                s = dt.isoformat()
        return s

def logging_config(log_filename, log_level, 
                   log_format = '%(asctime)s.%(msecs)03d - %(levelname)s - %(message)s', 
                   date_format='%Y%m%d_%H:%M:%S'):
    # Create a logger object
    logger = logging.getLogger()

    # Configure the logging level
    logger.setLevel(log_level)

    # Create a file handler
    file_handler = logging.FileHandler(log_filename)

    # Create a stream handler (to display logs in the notebook)
    stream_handler = logging.StreamHandler()

    # Create the custom formatter
    formatter = CustomFormatter(log_format, datefmt=date_format)

    # Set the formatter for both handlers
    file_handler.setFormatter(formatter)
    stream_handler.setFormatter(formatter)

    # Set the logging level for both handlers
    file_handler.setLevel(log_level)
    stream_handler.setLevel(log_level)

    # Add both handlers to the logger
    logger.addHandler(file_handler)
    logger.addHandler(stream_handler)

    return logger

def logging_test(logger):
    # Log messages
    logger.debug('This is a debug message')
    logger.info('This is an info message')
    logger.warning('This is a warning message')
    logger.error('This is an error message')
    logger.critical('This is a critical message')
    return 0

if __name__ == '__main__':
    log_filename = './log_test.log'
    print('log_filename*', log_filename)
    log_format = '%(asctime)s.%(msecs)03d - %(levelname)s - %(message)s'
    logger = logging_config(log_filename = log_filename,
                            log_format = log_format,                              
                            log_level = logging.DEBUG, #INFO,
                            date_format="%Y%m%d_%H%M%S")
    
    logging_test(logger)

When I use log_level = logging.DEBUG it does not work for me and produces only:

$ ipython local_functions.py
log_filename* ./log_test.log
(base)

when I use logging.INFO or higher levels it works as expected:

log_filename* ./log_test.log
20240104_211453.256 - INFO - This is an info message
20240104_211453.261 - WARNING - This is a warning message
20240104_211453.261 - ERROR - This is an error message
20240104_211453.262 - CRITICAL - This is a critical message

What might be the problem?