I too have had this issue. It only came after doing the most recent update of WordPress for our website. I tried Firebug, deactivated plugins, cleared my style sheet of customizations but I cannot find where it’s coming from. I did notice when I turned “on” comments for a WordPress page it went away, but of course I don’t want comments on every page.
For instance here: https://www.circleventure.net/mission-teams/