Recently I notice history.stackexchange.com has been keeping the connection open, i.e., the browser is constantly receiving information, which is very rude behavior for a web site because it steals CPU cycles from the client machine. This is sometimes called "hanging the browser". Has something changed in how the site is programmed?
Other Stack Exchange sites do not exhibit the same behavior and close the connection after the page is loaded, which is the proper thing to do; so, this seems to be unique to History.
I have checked the main source page and it is fine. It appears to be some secondary script that gets loaded after the main page.
Also, I notice if I experiment with my settings I get the following warning: