Registering field for block does not work

I created a block with acf_register_block_type which shows the block in editor which is complete fine. I did that this way,

//custom block with acf
function mab_register_acf_block_types() {
acf_register_block_type( [
'name' => 'blockquote',
'title' => __( 'Blockquote' ),
'description' => __( 'My blockquote block.' ),
'render_template' => dirname( file ) . '/blocks/blockquote/blockquote.php',
'category' => 'formatting',
'icon' => 'format-quote',
] );
}

if ( function_exists( 'acf_register_block_type' ) ) {
add_action( 'acf/init', 'mab_register_acf_block_types' );
}

But I wanted to register the field for this block which actually does not work.
The registration of field done this way
add_action('acf/init', function () {
if( function_exists('acf_add_local_field_group') ):

	acf_add_local_field_group(array (
		'key' => 'group_1',
		'title' => 'My Group',
		'fields' => array (
			array (
				'key' => 'field_1',
				'label' => 'Sub Title',
				'name' => 'sub_title',
				'type' => 'text',
				'prefix' => '',
				'instructions' => '',
				'required' => 0,
				'conditional_logic' => 0,
				'wrapper' => array (
					'width' => '',
					'class' => '',
					'id' => '',
				),
				'default_value' => '',
				'placeholder' => '',
				'prepend' => '',
				'append' => '',
				'maxlength' => '',
				'readonly' => 0,
				'disabled' => 0,
			)
		),
		'location' => array (
			array (
				array (
					'param' => 'block',
					'operator' => '==',
					'value' => 'blockquote',
				),
			),
		),
		'menu_order' => 0,
		'position' => 'normal',
		'style' => 'default',
		'label_placement' => 'top',
		'instruction_placement' => 'label',
		'hide_on_screen' => '',
	));

endif;

});

If I set the location to something else like post_type , it is okay, which means the code for registering the field is working for post_type but if I set the location to block == 'blockquote', it's not working.

Start by reproducing the acf_register_block_type and acf_add_local_field_group calls shown in the issue, using the acf/init entry point and the block location rule for blockquote. Compare the behavior with the working post_type location rule and verify whether the field appears for the registered block in the editor.