TypeError: Could not build a TypeSpec for KerasTensor(type_spec=TensorSpec(shape=(None, None, 4), dtype=tf.float32, name=None), name='tf.math.truediv/truediv:0'

[poor-soul]

We are trying to train Mask RCNN in
Python 3.10.12
tensorflow=2.9.1
keras=2.9.0

our dataset is annotated with 30 images, a sample to know how well it works.
we have encountered the error:
TypeError: Could not build a TypeSpec for KerasTensor(type_spec=TensorSpec(shape=(None, None, 4), dtype=tf.float32, name=None), name='tf.math.truediv/truediv:0', description="created by layer 'tf.math.truediv'") of unsupported type <class 'keras.engine.keras_tensor.KerasTensor'>.

Please help me in having a better understanding on encountering the error and how to solve it
Could anyone provide guidance on how to train Mask RCNN in in given specification(present tensorflow starts from 2.8.0), also providing insights on:

->dataset size
->How long will it take for training(to run one epoch and the whole training process as well)