Is it possible to change the form of text in Description field?


I’m trying to make the texts in the “Preview description” part Bold on our blog posting.

But when I publish, it shows the markup references __text __ .
And you go to preview mode, and it’s bold (no markup), but when you press publish and look at the actual blog on the website, it’s not in bold, and still shows the markup references on the actual blog page.
Seems like none of the options to change the form of text is not allowed for description part.

Is it some sort of bug? or is it just not allowed to make the description part bold?
Does anyone know how to fix this?