So the old large HDi Sky remote works with the new White Skybox if you change the mode (Codeset 3) on it

By holding the "SELECT" and NUMBER "3" buttons for 3 seconds.  After which you can control the White Skybox.  It works fine on my unit.

I presume this is IR since that old remote doesn't have bluetooth.

However I am now attempting to add this to my Harmony Elite, by learning the buttons.  But when I'm prompted to point the original (old Sky remote in Codest3 mode) remote at the Hub and press the button, the Hub doesn't recognise most of the buttons.

Anyone else try this? What is it about this IR Codeset that the Harmony can't learn?

(ps I know about setting up the HTPC/Tivo remote devices to control the Skybox via BLE.  Just trying to learn IR for my fam who have the IR only Harmony)