User blog comment:Rappy 4187/Technical Update: June 21, 2017/@comment-13301-20170625104224/@comment-126761-20170626145434

That's a bug affecting a small subset of users who utilize AdBlock software. Like all other browser extensions, we cannot guarantee that the site will work 100% as intended when using them. Given that, it's not a bug we have prioritized for fixing (and it's a bit more than a simple z-index issue).