This appears related to the addition of the new sub-menu option "Answers" in the menubar for the community. I run the same platform, but it didn't show up as a problem for me, so I suspect it may have something to do with the stylesheet you're using and us not updating that stylesheet to ensure it doesn't do that.

We'll take a look at it and try and fix it within the next day or two. Sorry about this.

DocJohn