Make sure you're doing as outlined in this support article:
Redownload TV shows and movies that you purchased --> https://support.apple.com/HT211825
You haven't hidden it?
iTunes Store: Hiding and unhiding purchases - http://support.apple.com/HT201322 - tip: https://discussions.apple.com/thread/7044546
If there's an issue when you redownload apps, movies, or other content from Apple, click here --> https://support.apple.com/HT211842
Possibility:
Legal - Apple Media Services - Apple - https://www.apple.com/legal/internet-services/itunes/us/terms.html - "DOWNLOADS You may be able to redownload previously acquired Content (“Redownload”) to your devices that are signed in with the same Apple ID (“Associated Devices”). You can see Content types available for Redownload in your Home Country at https://support.apple.com/HT204632. Content may not be available for Redownload if that Content is no longer offered on our Services." Always download everything to your computer and keep multiple backup copies on local storage.