[monster][/monster] functionality no longer working?

I noticed that the [ monster][ /monster] function which would display monster portrait icons in forum posts recently stopped working.

Is there a new way to easily insert monster portrait icons in posts?

 

Looks broken on my end.

Maybe you're using a different forums them? I'm using the Infirog theme.

EDIT: Nope, still broken when using other themes.

 

I tried in a completely different browser that I almost never use (Edge) and get the same result.