This way you can add a new tab.
In your view/frontend/layout
folder, create a xml file named catalog_product_view.xml
and add the following content. Do note the values to change. If you are adding this from a theme, then you will not have a view/frontend/layout
folder. Instead you will have to create either Magento_Catalog/layout
folder.
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column"
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<!--Product Main Content-->
<referenceContainer name="content">
<!--Detail tab section-->
<block class="Magento\Catalog\Block\Product\View\Details" name="product.info.details" template="Magento_Catalog::product/view/details.phtml" after="product.info.media">
<!--our custom tab -->
<block class="Magento\Catalog\Block\Product\View\Attributes" name="product.uniqueNameForTab" as="customTab" template="Magento_Catalog::path/to/custom-features-template-file.phtml" group="detailed_info">
<arguments>
<argument translate="true" name="title" xsi:type="string">Custom Tab</argument>
<argument name="sort_order" xsi:type="string">20</argument>
</arguments>
</block>
</block>
</referenceContainer>
</body>
</page>
If you are still facing problems, I have a working code which I added multiple tabs. Let me know.
description
value inMagento_Catalog/templates/product/view/attribute.phtml
with additional content from another attribute just doesn't seem right to me.