<xsl:sort> not working in XSLT PI mapping

I'm newbie to XSLT and I have below code which is not working for simple sort. Any help is appreciated.

<xsl:template match="ns0:MT_name">
<xsl:for-each select="name">
<xsl:sort select="name"/>
</xsl:for-each>
</xsl:template>

input is:

<?xml version="1.0" encoding="UTF-8"?>
<ns0:MT_name xmlns:ns0="http://example.com/sap/pi/TEST/xslt">
   <name>11</name>
   <name>88</name>
   <name>55</name>
</ns0:MT_name>

output expected:

<?xml version="1.0" encoding="UTF-8"?>
<ns0:MT_name xmlns:ns0="http://example.com/sap/pi/TEST/xslt">
   <name>11</name>
   <name>55</name>
   <name>88</name>
</ns0:MT_name>

Change <xsl:sort select="name"/> to <xsl:sort select="."/>. The current context is already name.

Try this XSLT 1.0 stylesheet:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:ns0="http://xyz.com/sap/pi/TEST/xslt">
  <xsl:output indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="ns0:MT_name">
    <xsl:copy>
      <xsl:apply-templates select="@*"/>
      <xsl:apply-templates select="name">
        <xsl:sort select="." order="ascending"/>
      </xsl:apply-templates>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>