Need Help - remote Daw by Komplete Kontrol not retained

O dear, I have a case of the Cubase Conundrums and need some help before I go crazy.
I have a Komplete Kontrol S49,which works well and functions as a DAW controller for Cubase almost as it should. Trouble is - Cubase will not remember it as an installed remote device and every time I change file or restart I have to install it again (Device-setup – add remote device). Although it’s listed as an available device it is never retained. It’s an irritation to have to do it again and again. I thought a macro might help but ‘add remote device’ is not available as a key command so got stuck there. The KK is installed as itself, by the way, not as a Mackie controller. I have cleaned out the preferences folder, but no change. The behaviours mentioned above and below are repeatable.
The next bit is even weirder. I can get the controller remembered if I add the Kontrol with a midi port for it set up with the “use device as ‘Direct Music’” checked. This succeeds in having the DAW control installed every time as it should. It also causes any use of the sustain pedal with the keyboard to result in hanging notes, making it unusable. Stranger still it only does this with some Steinberg instruments (Halion 5, Dark Planet, Padshop) and not others (Prologue, Retrologue) and not at all with N I plugin instruments. Checking the Timestamp boxes makes no difference to this behaviour.
Apart from “wtf is going on,” my question is why won’t Cubase remember this particular remote device between sessions or file changes where as it does for other controllers (CMC, Motif)?
Any thought anyone – please, it’s driving me nuts.