I have an iMac that I use for Home Sharing with an Apple TV, I store Films and TV episode on a Synology NAS drive. I used to be able, as long as my iMac was on, to play video content from the computers section of the Apple TV but now only content locally on the iMac shows up? When did hat happen? Is it just me? Can I get it to work again? Now the only way to show video is to start it air playing from the iMac or use the DS Video app.