Serviço de Selecionador de Idioma, muda a URL

Qual a versão do LumisXP que esta utilizando?

Oi Guilherme, é a versão 11.2.0. 

Estilo customizado, segue

<!-- $Revision: 104 $ $Date: 2015-09-14 13:01:19 -0300 (seg, 14 set 2015) $ -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" xmlns:ext="http://exslt.org/common" exclude-result-prefixes="ext">
	<xsl:import href="/lumis/doui/style/DouiControls.xsl" />
	<xsl:output omit-xml-declaration="yes" method="xml" />

	<xsl:template match="/">
		<xsl:if test="count(//locales/locale) &gt; 1">
			<xsl:apply-templates select="renderData/controls/control" />
		</xsl:if>
	</xsl:template>

	<xsl:template name="lum_formBodyControls">
		
		<div class="top-nav">
			<ul>				
				<li class="dropdown language-select">
					<a href="#" data-toggle="dropdown" title="${{lum_localize('Idiomas')}}">
						<i class="fa fa-globe-asia"></i>${lum_localize('Idiomas')}
						<i class="fa fa-caret-down"></i>
					</a>
					<ul class="dropdown-menu">
						<xsl:for-each select="//locales/locale">
							<li><a href="{url}" title="{name}"><xsl:value-of select="name" /></a></li>
						</xsl:for-each>
					</ul>
				</li>
			</ul>
		</div>
		
		<input type="hidden" name="locale" />
		<input type="hidden" name="currentUrl" />
		<script type="text/javascript">document.forms['<xsl:value-of select="//control[@type='lum_form'][1]/data/name" />'].elements['currentUrl'].value=window.location.href;</script>
	</xsl:template>

</xsl:stylesheet>

Experimente adicionar o atributo onClick no link do idioma que deseja selecionar.

<a href="{url}" title="{name}" onclick="{onClick}"><xsl:value-of select="name"/></a>