Damn. “First comment” theory is out. It’s something though.

I have had this issue show up on my own comments as well. (Even with using the I function in Connect or not.)

Also underscores have been italics for years across many platforms. It’s not always, but is generally. (Well, I have been using underscores as a pseudo-emphasis before markdown was even a thing.)

Edit: From a now deleted post, but you can see it in my history: