I have verified updated OS's, rebooted, logged out/in, even put both Apple TV and Mac on wired connections, but STILL the Apple TV cannot see the Mac Library home videos I added in the Apple TV app on the Mac. Is this common?
iMac 27″, macOS 13.2
Verify that both devices connect to the same home network. For Wi-Fi, that should be the exact same SSID network name. Restart the router too, in case that could use a refresher.
Verify that both the Mac and the Apple TV box have set the same Apple ID account for Home Sharing. Only matching accounts will have a detectable Library.
Name your Library uniquely, especially if you have more (potentially sharing) computers on your home network.
Use Home Sharing to share media from a computer to other devices - Apple Support
Mac home video library not appearing in Computers on Apple TV
