Getting 404 not found when using wp_dropdown_categories with taxonomies

Hey,

As topic states, im getting a 404 not found when uysing wp_dropdown_categories with taxonomies.

This code works just fine (regular wp_list_categories
it writes the url to the correct location; https:// domain /bransch/kladbutik/

<?php
$taxonomy     = 'Bransch';
$orderby      = 'name';
$show_count   = 0;
$pad_counts   = 0;
$hierarchical = 1;
$title        = '';

$args = array(
  'taxonomy'     => $taxonomy,
  'orderby'      => $orderby,
  'show_count'   => $show_count,
  'pad_counts'   => $pad_counts,
  'hierarchical' => $hierarchical,
  'title_li'     => $title
);
?>

<ul>
<?php wp_list_categories( $args ); ?>
</ul>

This is the code that doesnt work, it rights the url to https:// domain /?cat=9

<li id="categories">
	<h2><?php _e('Posts by Category'); ?></h2>
	<form action="<?php bloginfo('url'); ?>/" method="get">
	<div>
<?php
$select = wp_dropdown_categories('show_option_none=Select category&show_count=1&orderby=name&echo=0&taxonomy=Bransch');
$select = preg_replace("#<select([^>]*)>#", "<select$1 onchange='return this.form.submit()'>", $select);
echo $select;
?>
	<noscript><div><input type="submit" value="View" /></div></noscript>
	</div></form>
</li>

Can someone please help me out with what im doing wrong, i’ve been stuck with this problem for some hours and its killing me.