I have the latest Airport Extreme base station. My main media computer is a Windows 10 desktop wired into the router. I find that when I connect my Apple TV to the 5Ghz wifi band the speeds are MUCH faster (tested with the Speedtest app). I don't see any YouTube buffering/resolution changing on 5Ghz but I do on the 2.4Ghz band. However, when I connect to the 5Ghz band the Computer app on the ATV says I need to turn on Home Sharing but it is on and iTunes is running. If I switch over to the 2.4Ghz band Home Sharing works great. If I switch back to the 5Ghz it doesn't work anymore. This is verified without rebooting or restarting any hardware. I do have an older Airport Extreme in my living room that I'm using as a wifi extender. Could that be the problem?