Hello,
I just purchased CB3 and am building my first track, and have found that when I have two AUv3 instruments, my midi keyboard doesn’t follow the “in focus” instrument, but sometimes is locked to one of the instruments, or plays both at the same time. I have the midi settings in the app to follow the armed track, but that doesn’t seem to have any affect or change of behaviour. I have tried a few keyboards but there is no difference.
I just bought the app so have no idea if this was working in a previous version, although things work properly in CB2.