I bought a film on my iPad and can't get it on my Mac

Hi yall,

I recently bought a film on my iPad with iTunes (full buy, not rental).

I dowloaded it on my iPad and it works fine.

I can download it on my AppleTV too, but when I try to get it on my Mac, I don't get the download possibility but rather a buy option.

Of course, I don't intend to buy it twice.

All my devices share the same iCloud account and I don't have other sharing problems (music, photos, ...)

Anyone to help me understand and solve this problem?

Thanks

Jean