I have below xsl code which is not giving me sort on SEC_Match element:

    <xsl:template match="*[SEC]">
    <xsl:copy>
        <xsl:apply-templates select="@*"/>
        <xsl:for-each select="*">
            <xsl:variable name="a" select="substring-before(@UID,'^')"/>
            <xsl:choose>
                <xsl:when test="self::SEC[$a = substring-before(following-sibling::SEC[1]/@UID,'^')]|self::SEC[$a = substring-before(preceding-sibling::SEC[1]/@UID,'^')]">
                    <xsl:for-each select="self::SEC[$a = substring-before(following-sibling::SEC[1]/@UID,'^')]|self::SEC[$a = substring-before(preceding-sibling::SEC[1]/@UID,'^')]">
                        <xsl:sort select="@STARTEFFDATE" data-type="number" order="descending"/>
                        <SEC_Match>
                            <xsl:apply-templates select="@*"/>
                            <xsl:apply-templates/>
                        </SEC_Match>
                    </xsl:for-each>
                </xsl:when>
                <xsl:otherwise>
                    <xsl:copy>
                        <xsl:apply-templates select="@* | node()"/>
                    </xsl:copy>
                </xsl:otherwise>
            </xsl:choose>
        </xsl:for-each>
    </xsl:copy>
</xsl:template>