Home Sharing album not working as screen saver source in tvOS 27.2

A useful test first, because it splits the problem in two: open the Computers app on the Apple TV and check whether the shared library and the album still show up and open there.

If the library does not appear in Computers either, Home Sharing authentication broke in the update, which is the common failure. Fix it by re-signing both ends: on the computer, turn Home Sharing off and back on in the Music or TV app (and in Photos check that sharing of the library is still on under its settings), and on the Apple TV sign out of your account under Settings > Users and Accounts and sign back in, then restart both. The computer also has to be awake and on the same network whenever the screen saver goes looking for the album.

If the album plays fine in Computers but is simply no longer offered in Settings > General > Screen Saver, that is a tvOS 27.2 regression rather than your setup, and it is worth reporting through Feedback Assistant with exactly that detail (works in Computers, missing as a screen saver source).

Workaround that works today: put the same album in iCloud Photos, as a regular album or a Shared Album, and choose it as the screen saver source from the Photos option instead. The iCloud path does not depend on the computer being awake, which makes it the more reliable of the two anyway.