The Faderport isn’t well integrated with Cubase when using Mackie Control.
Now that Cubase 12 has MIDI Remote, you should use this instead of Mackie Control.
Someone has made a great script for Faderport V2 / ioStation 24c, you can find the details in the following topic :
The script has been since updated with improved features, you should download it from the most recent posts, not the first one, here’s the link for the latest version anyway :