Netflix follow download problem?

Why can't I download the episode of certain series even though I have premium

Not all titles are downloadable. Most films and series can download but some movies such. Titanic or Planet of the Apes are not going to download no matter what package you have. Why I do not know unfortunately.

This is due to the contracts that Netflix has concluded with the rights holders of the formats. If rightholders have not given their consent to the Download option, then this feature will not be offered.