logger behaviour

[setdetnet]

This setup in python 3.10 is not logging DEBUG to log file.
As in the last line....rootLogger.debug("debugging MantisMigrateAdditionalInfo.py")
Why so?

for handler in logging.root.handlers[:]:
    logging.root.removeHandler(handler)
inputFileName="in.csv"
rootLogger = logging.getLogger("MantisMigrateAdditionalInfo")
rootLogger.setLevel(logging.DEBUG)
loggingFileName = inputFileName[0 : -4]
loggingFileName += "_additional.log"
logFormatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
fileHandler = logging.FileHandler(filename=loggingFileName, mode='w')
fileHandler.setFormatter(logFormatter)
fileHandler.setLevel(logging.DEBUG)
rootLogger.addHandler(fileHandler)
consoleHandler = logging.StreamHandler(sys.stdout)
consoleHandler.setFormatter(logFormatter)
consoleHandler.setLevel(logging.INFO)
rootLogger.addHandler(consoleHandler)

rootLogger.info("starting MantisMigrateAdditionalInfo.py")
rootLogger.debug("debugging MantisMigrateAdditionalInfo.py")