Unsolved 'tensorflow.python.keras.utils.generic_utils' has no attribute 'populate_dict_with_module_objects'

I'm doing a Detection model and I'm in the step of Configuration For Transfer Learning. The error shows when I try to do these import:

import tensorflow as tf
from keras import utils
from object_detection.utils import config_util
from object_detection.protos import pipeline_pb2
from google.protobuf import text_format

I have already insert

def populate_dict_with_module_objects(target_dict, modules, obj_filter):
  for module in modules:
    for name in dir(module):
      obj = getattr(module, name)
      if obj_filter(obj):
        target_dict[name] = obj

in C:\Users\Chiara\AppData\Local\Programs\Python\Python38\Lib\site-packages\tensorflow\python\keras\utils but it doesn't work.

I don't have tf.nighly installed.

This is the traceback:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-74-1865ce426368> in <module>
----> 1 from tensorflow.keras.utils import to_categorical
      2 import tensorflow as tf
      3 from keras import utils
      4 from object_detection.utils import config_util
      5 from object_detection.protos import pipeline_pb2

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\__init__.py in <module>
     39 import sys as _sys
     40 
---> 41 from tensorflow.python.tools import module_util as _module_util
     42 from tensorflow.python.util.lazy_loader import LazyLoader as _LazyLoader
     43 

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\__init__.py in <module>
     82 from tensorflow.python import data
     83 from tensorflow.python import distribute
---> 84 from tensorflow.python import keras
     85 from tensorflow.python.feature_column import feature_column_lib as feature_column
     86 from tensorflow.python.layers import layers

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\__init__.py in <module>
     25 
     26 # See b/110718070#comment18 for more details about this import.
---> 27 from tensorflow.python.keras import models
     28 
     29 from tensorflow.python.keras.engine.input_layer import Input

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\models.py in <module>
     22 from tensorflow.python.framework import ops
     23 from tensorflow.python.keras import backend as K
---> 24 from tensorflow.python.keras import metrics as metrics_module
     25 from tensorflow.python.keras import optimizers
     26 from tensorflow.python.keras.engine import network

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\metrics.py in <module>
     35 from tensorflow.python.framework import tensor_spec
     36 from tensorflow.python.keras import backend as K
---> 37 from tensorflow.python.keras.engine import base_layer
     38 from tensorflow.python.keras.engine import base_layer_utils
     39 from tensorflow.python.keras.losses import binary_crossentropy

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\engine\base_layer.py in <module>
     49 from tensorflow.python.keras import backend
     50 from tensorflow.python.keras import constraints
---> 51 from tensorflow.python.keras import initializers
     52 from tensorflow.python.keras import regularizers
     53 from tensorflow.python.keras.engine import base_layer_utils

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\initializers\__init__.py in <module>
    125 # from ALL_OBJECTS. We make no guarantees as to whether these objects will
    126 # using their correct version.
--> 127 populate_deserializable_objects()
    128 globals().update(LOCAL.ALL_OBJECTS)
    129 

c:\users\chiara\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\keras\initializers\__init__.py in populate_deserializable_objects()
     83     v2_objs = {}
     84     base_cls = initializers_v2.Initializer
---> 85     generic_utils.populate_dict_with_module_objects(
     86         v2_objs,
     87         [initializers_v2],

AttributeError: module 'tensorflow.python.keras.utils.generic_utils' has no attribute 'populate_dict_with_module_objects'

Also from the pip list I understand that I have installed tensorflow 2.4.1 but if I do tf .__ version__ it tells me 2.2.0. I have Python 3.8.1.

Thank you so much !!