Custom Layout Update on product not working for description and short description

Question

We're using Magento 2.2.6. If we create a custom layout update for the description and short description of a product nothing happens in frontend. Still the old fields are outputted.

How can we change the attribute which is used for the values which are presented in the frontend?

<referenceBlock name="product.info.overview">
    <arguments>
        <argument name="at_call" xsi:type="string">getInternalShortDescription</argument>
        <argument name="at_code" xsi:type="string">internal_short_description</argument>
    </arguments>
</referenceBlock>
<referenceBlock name="product.info.description">
    <arguments>
        <argument name="at_call" xsi:type="string">getInternalDescription</argument>
        <argument name="at_code" xsi:type="string">internal_description</argument>
    </arguments>
</referenceBlock>

Answer 1

Add following:

<pre><referenceBlock name="product.info.overview">
<arguments>
    <argument name="at_call" xsi:type="string">getInternalShortDescription</argument>
    <argument name="at_code" xsi:type="string">internal_short_description</argument>
    <argument name="css_class" xsi:type="string">internal_short_description</argument>
    <argument name="at_label" xsi:type="string">none</argument>
    <argument name="title" translate="true" xsi:type="string">Internal Short Description</argument></arguments></referenceBlock><referenceBlock name="product.info.description">
<arguments>
    <argument name="at_call" xsi:type="string">getInternalDescription</argument>
    <argument name="at_code" xsi:type="string">internal_description</argument>
    <argument name="css_class" xsi:type="string">internal-description</argument>
    <argument name="at_label" xsi:type="string">none</argument>
    <argument name="title" translate="true" xsi:type="string">Internal Description</argument>
</arguments>