cannot download purchased movies err 21

So some of my purchases (Movies, TV Series) cannot be download at all on my mac. tried everything:

• logout login
• reauthorize
• on LAN
• on WIFI
• on a completely different internet connection
• Firewall off
• IPS off
• different DNS Servers

I click the cloud download button and then immediately without even trying it goes to -1% and then error cannot be download unknown error err 21. check my internet connection. There is enough space on the disk of the media Library. Currently 8TB of free space. So anybody got any suggestion?

And please dont come with reset your device. I wont do that since i would loose all my settings and stuff. Some movies work others dont. Newest example is the topgun bundle. It wont download at all. Streaming works totally fine. On iPhone 12 Pro the download works without problems!

Why do i want to have all media offline? - Because i want to be able to watch movies offline without having to rely on internet connection.

Thanks and best regards,

Gil