Justoverclock That file is all the compiled JS for the site. I'm not sure why I'm unable to replicate this on your site, the one thing that could come to mind is that it only affects admins for some reason? Or a browser issue (which browser are you using) but you said it also occurs on mobile so I doubt that.
If you would like me to take a look under an admin account, my username on your site is askvortsov
. If not, absolutely no pressure