web page slow and unresponsive

In the last month or so, the web page has become super slow and unresponsive? Particularly loading a recent chat from the side bar, or often after entering a new chat message, the page hangs whilst the url updates.

Not sure why this is happening, until now everything was super slick and fast. really affecting the user experience.

Mostly using Google Chrome on Linux but I even have the same problem on mobile (android).