Make sure that the setting for multiple screens is "mirrored". By default it has them as separate devices.For the last match I connected my Chromebook to the TV by HDMI, all seemed fine but all I could get on the TV was my Home Page not the page I was actually looking at on the PC. It was the same for all websites, BBC News etc, any help appreciated. Thanks.
Where do you find the settings for multiple screens, and then mirrored?Caught me out the first time as well.
Just to add, you need to connect the HDMI first or else the options to mirror won't be there.The cog-wheel - devices - displays