Thank you Skip for taking the time to reply. It doesn't appear that the MPK mini has a local setting. I have the AKAI MPK Mini, not the MPK Mini II it that helps clarify the problem.
It seems when I create the second instrument track, a few things are happening: Second instrument track is not showing up in my mix window down below, but it is showing up along the left side along with the other tracks from top to bottom.
Also, if I create a new session (song) the MPK is not allowing me to add an input or output in the tracks to the left. Same setting between new & old song files. Any help would be great, thanks so much!