Cubase 12 midi issue

I believe the MIDI Remote is only pre-programmed for the Akai MPK Mini Mk3. And not any other Akai controller:

There’s also this related older forum thread:

EDIT: Your best chance would probably be to make your own setup for your model of controller:

On the outside chance that you’re much adventurous and into programming, there’s an interesting video of someone who has made a different Akai controller work. But it’s not for everyone, since it involves changing JavaScript programming code. It’s not even for your particular model, but just in case you’re interested anyway: