Build produces fatal error when processing nested topics with short descriptions

[nosaj3]

I'm getting a fatal error when attempting to process a map that includes nested topics with short descriptions. The same set of topics is succeeding when I unnest them. The error I receive is:

Error: Fatal error during transformation using /Users/jason.davis/Sandbox/test/tools/dita-ot/plugins/org.dita4publishers.html5/xsl/map2html5.xsl: A sequence of more than one item is not allowed as the first argument of normalize-space() ("Test HWX Concept", "Short description stuff") ; SystemID: file:/Users/jason.davis/Sandbox/test/tools/dita-ot/plugins/org.dita4publishers.html5/xsl/commonHtmlExtensionSupport.xsl; Line#: 469; Column#: -1

d4p plugin version: dita4publishers-toolkit-plugins-1.0.0RC26-ot-2.4 dita ot version: 2.5.3 Sample of succeeding and failing project: test.zip

[nosaj3]

This code appears to be the culprit and seems problematic:

    <xsl:apply-templates select="." mode="related-links:group-unordered-links">
        <xsl:with-param name="nodes" select="descendant::*[contains(@class, ' topic/link ')]
       [count(. | key('omit-from-unordered-links', 1)) != count(key('omit-from-unordered-links', 1))]
       [generate-id(.)=generate-id((key('hideduplicates', concat(ancestor::*[contains(@class, ' topic/related-links ')]/parent::*[contains(@class, ' topic/topic ')]/@id, ' ',@href,@scope,@audience,@platform,@product,@otherprops,@rev,@type,normalize-space(child::*))))[1])]"/>
    </xsl:apply-templates>

This apply templates instruction is attempting to process a sequence of items through a normalize space function. If I limit this instruction to just one item:

normalize-space(child::*[1]))))[1])]"

My builds no longer fail. Obviously, this isn't a viable fix to the issue as it just essentially kicks the can down the road that introduces potential problems with related links. This begs the question: why are short descriptions caught up in processing of potential related links?