Netflix has managed to annoy a good number of its users with an announcement about an upcoming update to its Windows 11 (and Windows 10) app: support for adverts and live events will be added, but the ability to download content is being taken away.
Netflix must realize that it's a huge frustration for people who relied on offline downloads to watch content without internet access: on planes, trains, and campsites, and anywhere else where Wi-Fi is unavailable or unreliable.
There's a small chance that Netflix will change its mind if it gets enough complaints, but the streaming service seems determined to add as many money-making features as possible, while taking away genuinely useful ones.
I don't see that feature listed at https://f-droid.org/en/packages/org.jellyfin.mobile/? I have never used Jellyfin though - it looks quite awesome! - and so know nothing about it, I mention here to say that it might either depend on how you install it or perhaps it's a plugin.