There are site settings where admins can decide whether to prioritize name or username in discussions. So you can fix this on your own discourse instance but admins of other instances might have other preferences.
Here’s how I have them set:
to get:
My username is also suppressed, like yours, for the reason explained by Jeff above. I like it, and in fact on my instance we have a real name policy and nearly all staff appear like this because their username and name are the same.