text_size default value for button in child module doesn't work

[annq2]

When defining buttons in child modules, default value for font-size doesn't work:

function get_advanced_fields_config() {
	return array(
		'button' => array(
			'button' => array(
				'label' => esc_html__( 'Button', 'et_builder' ),
				'text_size'           => array(
				      'default' => '56px',
				),
			), 
		),
	);
}

Value is always 0

The problem I am experiencing is the font-size: 0px is being outputted on the frontend and buttons are not visible.