I've been checking your DOC after exporting it to DOCX. The problem is that you're merging more than one placeholder and
string in the same cell. As using this method
$docx->addTemplateVariable('P_GName', 'image.png', 'image')
the image is replaced with an altchunk tag, Word is unable to read w:r tags that has an altchunk tag and more content.
So the solution it's to set a cell for each placeholder or use replaceTemplateVariableByHTML method that don't use altchunk but other WordML tags.