duh, I though default_value was a type of variable for ACF :$ I just change it for $value and it worked.
function my_text_value_group_type( $value, $post_id, $field ) {
$value = isset( $_GET['foo_name'] ) ? $_GET['foo_name'] : $value;
return $value;
}
add_filter('acf/load_value/key=<field_key>', 'my_text_value_group_type', 10, 3);
Thank you
