Apple TV screen saver

I'm sure you have already tried a reboot but just in case that is the only other thing I can recommend at this time. Apart from that it may be wise to contact Apple support so you can run through things in real time.

Can you elaborate?

Are other screensavers working, such as the underwater series?

Try switching to one of the other pre-loaded photo screensavers, or even try your own, and then switch back.