Hmm that is weird adding the breadcrumb like this worked for me. Either function you use is fine though.
function rkk_breadcrumb_text() {
$args['before'] = '<div class="bbp-breadcrumb"><p><span class="bbp-breadcrumb-text">You Are Here: </span>';
$args['sep'] = ' / ';
return $args;
}
add_filter('bbp_before_get_breadcrumb_parse_args', 'rkk_breadcrumb_text');