Im having the same issue, that and chrome “conveniently” downloads an “offline” version of the website from earlier in the day so when I go to it it “faster page loaded from earlier” that doesn’t work when you refresh the site to see new activity…
I’ve had this happen a few times using Firefox with Adblock Plus but not over the past week or so. I always stay logged in so that might have something to do with it.
In a internet world where some video, hidden on the side of the page, may start blasting away at full volume, a pop up in the middle of the screen is only mildly annoying.