AttributeError: 'DataFrameIterator' object has no attribute 'copy'

When I am trying to set up train and validation datasets reading from the same dataframe with 80-20 split for train-validation data, getting this error

img_data_generator = ImageDataGenerator(rescale=1/255, 
                                            validation_split=0.2,
                                            rotation_range = 180,
                                            horizontal_flip = True,
                                            vertical_flip = True,
                                           )
    
    
    
    
    
    ## Recreate datasets from dataframe
    train_df = img_data_generator.flow_from_dataframe(dataframe=train_df,
                                                        directory="./frames/",
                                                        x_col="img_name",
                                                        y_col= "label_names",
                                                        target_size=(224, 224),
                                                        class_mode='categorical',
                                                        batch_size=32,
                                                        subset='training',
                                                        shuffle=True,
                                                        )
    
    val_df = img_data_generator.flow_from_dataframe(dataframe=train_df,
                                                        directory="./frames/",
                                                        x_col="img_name",
                                                        y_col="label_names",
                                                        target_size=(224, 224),
                                                        class_mode='categorical',
                                                        batch_size=32,
                                                        subset='validation',
                                                        shuffle=True,
                                                        )
    
    After this getting this error:
    AttributeError: 'DataFrameIterator' object has no attribute 'copy'