Certain web page blanks second monitor screen

[ssherlock]

This is a weird one but in Ubuntu 15.10 running on a laptop with a secondary monitor if I visit a certain weather site - http://www.bbc.co.uk/weather/ - and then click on an actual day the screen will go blank.

This happens EVERY time and in both Chrome and Firefox. I have to go onto the laptop screen, get the menu and quit the browser to get the screen to come back on.

It's very weird - so weird that if I hadn't seen it with my own eyes I wouldn't believe it!

I haven't found any other page that this happens on. The monitor is an LG (it does NOT happen if I view the page on my laptop screen).