Cannot watch downloaded movies

Why doesn't it show the downloaded movies …

Is this perhaps about Home Sharing, to access content on your Mac from the Apple TV box?

Are these movies downloads from the Apple iTunes Store or video files from other sources?

Note that Home Sharing files appear in the Computers app on Apple TV box, not in the TV app on Apple TV.

Note that untagged files for Home Sharing would get listed as Home Videos.

Note that Home Sharing isn’t supported through the Apple TV app on third party devices.

… they are in my library …

Do you see them in the Library section of the TV app on Mac?

For ‘external’ files, did you add them to the TV app?

… and term not expired?

Not sure what that means? Please elaborate.

“28 days left”

This 30 day countdown would appear for unwatched rented movies (with 48 hour availability once playback has started). It may need online connectivity to the Store/account for this clock verification.

Downloaded movies from the iTunes Store should be playable offline on the device on which they were downloaded. It wouldn’t be valid for copies from other devices, and it wouldn’t stream to other devices (AirPlay) without an online authorization check. I don’t think that Home Sharing works for rented material, although I don’t have a current rental to test.

Download TV shows and movies that you purchased - Apple Support

Rent movies from the Apple TV app - Apple Support

Rentals can be downloaded to one device at a time.

Rentals are not available through Family Sharing.

If you need further assistance, please contact the Apple Support staff.

Then please contact the Apple Support staff for further assistance.

They should be able to verify your account and purchases for anomalies.

Also please review: If you can't watch or stream movies and TV shows in the Apple TV app - Apple Support

see if that contains possible actions that you haven’t taken yet.