iTunes or AppleTV disconnects from Home Sharing
Since MacOS 10.11 (El Capitan) or iTunes 12.3.0.44, my AppleTV loses the connection to iTunes Home Sharing (or possibly, iTunes disconnects from Home Sharing..?). I can stream podcasts from my computer for awhile, but after an indeterminate amount of time, like an hour or two, the AppleTV loses the connection to my computer, and the default "connect to home sharing" message shows up on the AppleTV home screen. Restarting iTunes fixes this problem for another hour or two.
I've never had this issue before, so I'm certain it's due to either the new MacOS or the new iTunes. Is there an easy way to troubleshoot this without losing my settings?
AppleTV gen 3
5GHz network with all Apple hardware (Airport Extreme, new Airport Express, Retina iMac)
Apple TV (3rd generation)