Hello,
The initial value is not supported by the HTML to DOCX transformation, so you can see a weird output if you try to use it. In your script, the paragraphs aren't removed in the DOCX output, but the spacing is set to 0 for all paragraphs:
<w:p>
<w:pPr>
<w:widowControl w:val="on"/>
<w:pBdr/>
<w:spacing w:after="0" w:before="0" w:line="240" w:lineRule="auto"/>
<w:ind w:left="0" w:right="0"/>
<w:jc w:val="left"/>
</w:pPr>
<w:r>
<w:rPr>
<w:color w:val="FF0000"/>
</w:rPr>
<w:t xml:space="preserve">This is a test.</w:t>
</w:r>
</w:p>
Regards.