avf_magazine_header_content filter

Hi, in Enfold 5.7 I’d like to add an ACF field value to magazine headers. In the file \wp-content\themes\enfold\config-templatebuilder\avia-shortcodes\magazine\magazine.php I found the following code line (1559):
$header_content = apply_filters( 'avf_magazine_header_content', $header_content, $entry );
That looks exactly like the right way for a header content modification. :-)
I added a respective filter in my child theme’s functions.php:

add_filter('avf_magazine_header_content', 'avf_magazine_header_content_custom_query');
function avf_magazine_header_content_custom_query ( $header_content, $entry ) {
	$acf_field_value = get_field('plz', $entry->ID);
	if ($acf_field_value) {
		$header_content['plz'] = '<div class="acf-field-value">' . $acf_field_value . '</div>';
	}
	return $header_content;
}

But this throws an error saying just 1 parameter was passed but 2 are expected.
It seems that just $header_content is passed to my custom function. But I need the $entry parameter here as well, because without $entry->ID I cannot retrieve the ACF field value. In magazine.php there are 2 parameters passed.
Any clue why $entry is not received by my custom function?