Missing expired stamp on expired badges

Hi.

Not sure if it is a bug, but on several installations I noticed that the "Expired" stamp on expired badges is not displayed anymore. Instead there is an exclamation mark above the badge image.

I could not find any information about this change and the Docs articles still show the stamp. Even the latest badge renderer code still got the stamp icon.

When deleting the line

'core:i/expired' => 'fa-exclamation text-warning',

on

/lib/classes/output/icon_system_fontawesome.php

the stamp appears.

So is this a bug or some kind of feature?

Greetings.