Cubase 10.5 and Montage coordination

I use Cubase 10.5 and also own a Yamaha Montage. I’m running into problems.

  1. When I choose a performance in the Montage that has more than one part and record to midi I can not use my curser to chick on the note and hear that note in the midi editor. No sound. For example, if that performance has two parts I can separate the two notes and the bottom note will be heard. But if they remain layered, clicking on the note does not create a sound. If I use a performance that only has one part, midi editor woks fine
  2. If I record a performance that has two parts and then decide I want to change to a performance that has three or more parts, only the first to parts will be played, requiring that I re-record using the new performance.
  3. When using the Montage as a midi controller, and using sounds from a program like Native Instruments or EZKeys I have to make sure I choose a performance with only one part.
  4. From time to time my Montage grabs a hold of a note and plays it forever. If I close Cubase and restart the note continues to play. The only way to stop it is to turn the Montage off and then on again.

Help.