Steps to reproduce the issue

In either J3.10 or J4.0.5 create a custom fields. I used a basic 'text' field.
In the Options tab, add a class for 'Field Class' and one for 'Label Class (Form)'.
Create or edit an article and add some text to the field.
View the article on the front end and use the browser's inspector.

Expected result

The field should be wrapped in a span with the associated class, e.g.

<span class="field-label my-field-class">Field label</span>
<span class="field-value my-label-class">Text of field</span>

Actual result

<span class="field-label ">Field label</span>
<span class="field-value ">Text of field</span>

System information (as much as possible)

Additional comments