Mackie HUI issue in Cubase 9.020

Each time I try setting up either Novation Launch Control XL or Novation LaunchKey49 to be used as MIDI controllers Cubase begins generating a non-stoppable MIDI IN signal, which means that as soon as I add a VST it makes an endless pulsing sound like I keep quickly pushing a key on my midi keyboard, which I don’t :exclamation: :confused: Both Novation devices are officially can be used as Mackie HUI and I don’t get the same behavior in Logic or Studio One 3. :unamused:
Any insight would be greatly appreciated.
Thank you.