I'm trying to mirror an HP Spectre laptop to my Roku+ stick. I've gone into W10 settings and searched for wireless device. Roku then asks for permission to connect, after which I see my desktop on my television screen, along with the taskbar along the bottom. However, when I open up an app such as a browser, it's not shown on the television. I just see the desktop, no matter what I'm doing on my PC. Any idea what I'm doing wrong?