Two underscores incorrectly italicise text?

[thebeachcomber]

Platform: website

Browser: Chrome

On my profile, I have this line typed:

This has always generated a hyperlink (as it should) to that user’s profile.
But as of this morning, the underscores either side of ‘sydney’ now italicise it and remove the hyperlink:

[carrieseltzer]

Thanks for the report, @beachcomber. This is related to an update earlier today to allow for markdown formatting in comments, but we’re working through some bugs that popped up in implementation.

[yayemaster]

The update has caused many changes, including formatting and bug fixing.

[kueda]

Sorry about that, should be fixed now. Supporting Markdown has all kinds of fun side-effects.