following error while training the model using "model_main.py": AttributeError: 'WeightSharedConvolutionalBoxPredictor' object has no attribute 'inputs'

Tensorflow version: 2.2.0
I started training the model using the below command

python model_main.py --pipeline_config_path=ssd_mobilenet_v1_fpn_640x640_coco17_tpu-8/pipeline.config --model_dir=training/ --num_train_steps=50000 --sample_1_of_n_eval_examples=1 --alsologtostderr

I get the below error
Traceback (most recent call last):
File "model_main.py", line 108, in
tf.app.run()
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow/python/platform/app.py", line 40, in run
_run(main=main, argv=argv, flags_parser=_parse_flags_tolerate_undef)
File "/opt/conda/lib/python3.7/site-packages/absl/app.py", line 299, in run
_run_main(main, args)
File "/opt/conda/lib/python3.7/site-packages/absl/app.py", line 250, in _run_main
sys.exit(main(argv))
File "model_main.py", line 104, in main
tf.estimator.train_and_evaluate(estimator, train_spec, eval_specs[0])
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/training.py", line 472, in train_and_evaluate
return executor.run()
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/training.py", line 613, in run
return self.run_local()
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/training.py", line 714, in run_local
saving_listeners=saving_listeners)
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 349, in train
loss = self._train_model(input_fn, hooks, saving_listeners)
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1182, in _train_model
return self._train_model_default(input_fn, hooks, saving_listeners)
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1211, in _train_model_default
self.config)
File "/home/jupyter/.local/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1170, in _call_model_fn
model_fn_results = self._model_fn(features=features, **kwargs)
File "/home/jupyter/.local/lib/python3.7/site-packages/object_detection/model_lib.py", line 543, in model_fn
update_ops=detection_model.updates(),
File "/home/jupyter/.local/lib/python3.7/site-packages/object_detection/meta_architectures/ssd_meta_arch.py", line 1350, in updates
self._box_predictor.inputs))
AttributeError: 'WeightSharedConvolutionalBoxPredictor' object has no attribute 'inputs'