@theophila : The WooCommerce pages do not contain the <article class="hentry">
. The content and the Html are also controlled by the plugin. The updates to the plugins might have affected to the design as well. If you would like to have a white background with red border on top as in the other pages. Go to Appearance=> Customize => Additional css and add the following css.
.post-type-archive-product .woocommerce-wrap, .single-product .woocommerce-wrap, .woocommerce-page .woocommerce-wrap {
background-color: #fff;
border-top: 2px solid #cc2b3a;
-webkit-box-shadow: 0 2px 2px rgba(0,0,0,0.12);
-moz-box-shadow: 0 2px 2px rgba(0,0,0,0.12);
box-shadow: 0 2px 2px rgba(0,0,0,0.12);
}
The WooCommerce shop is styled as you may check the style.css file with class name as .woocommerce. Let me know if you have any more issues.
Regards,
Tikaram