problème résolu :
Remplacer:
<div itemprop="review" itemscope itemtype="http://schema.org/Review" style="display:none">
<span itemprop="author">{Configuration::get('PS_SHOP_NAME')}</span>
Par ceci:
<div itemprop="review" itemscope itemtype="http://schema.org/Review" style="display:none">
<div itemprop="author" itemtype="https://schema.org/Person" itemscope>
<meta itemprop="name" content="{Configuration::get('PS_SHOP_NAME')}"></div>