I'm trying to register a HDD for Recording so that I can try to bin my Sky Subscription. I've tried 2 different Western Digital  HDD but I don't have the option to Register them for Recording. I do get the option to register them for Storage and the can be formatted and achieve the 256GB as per below. Without registering them for Storage the 1TB HDD are recognised but there is no option to Register for recording.

https://www.sony.co.uk/electronics/support/televisions-projectors-lcd-tvs-android-/kd-55xf9005/artic...

https://www.sony.co.uk/electronics/support/televisions-projectors-lcd-tvs-android-/kd-55xf9005/artic...

What am I doing wrong.