I have the same problem at least once or twice a week. We need to test our devices using VPNs -- it seems when the Apple TV connects to a different network than the Mac it obviously disconnects from Xcode (I really miss the USB port where we could debug no matter what network the Apple TV was on... please add that back Apple). When I reconnect my Apple TV to the same network as my Mac it is hit or miss whether it will reconnect to Xcode or not. If it doesn't, no amount of removing/ re-pairing the device works. Only solution for me is to reboot my Mac. If there is some easier way I would be delighted to hear it. Maybe there is some cache I can clear manually from the mac rather than completely disrupting my day with Mac reboots every time?