Steps to reproduce the issue

add a class like "myclass" to an article intro image
add an articles module that displays at least this article

Expected result

to see the class in the <figure class="myclass"><img src="... ..." ></figure> output of the module

Actual result

No class

System information (as much as possible)

Joomla! 5.4.2
PHP 8.4.17
Debian 6.1.162-1

Additional comments

The class is present in normal and blog display
Edit: in normal and blog display, the class is in the <figure tag, so that's where it should go in the article module too!