This is computer User Interface 101. Tab is a very ethical computer keyboard key, when computers first came about, a lot of thought went into properly implementing Tab and implementing it in a logical order of cueing fields and buttons in an order that the user is likely to use/follow.
Sometimes it works in Cubase, sometimes it works but is in a completely random/non-sensical order, and sometimes it works but doesn’t show its cued: example:
Adding MIDI tracks, it does tab to ‘Count’… but it doesn’t show that it has tabbed to count, and requires me to press enter to cue the count field. Whereas, Enter should simply cut straight to ‘Add Track’/Confirm in this particular window. I have to Tab to ‘Add Track’ which also doesn’t show I’ve tabbed to ‘Add Track’.