This one is kind of hard to explain.
I have two instances of Komplete Kontrol opened on two different MIDI tracks. When I put some notes on the piano roll of one of them and then select the other MIDI track that has nothing on it and hit play, the notes on the piano roll triggers both tracks. So I get two conflictive sounds playing the same notes. If I don't select the other track, it doesn't happen.
I've tried using two different plugins (Komplete Kontrol and LABS) and that also happens.
What's the problem here? Is it something about the MIDI input and output?
Thanks for helping me. The problem was that I couldn't find the rest of the information on the track. The "dropdown" button (those two arrows that expand or collapse the track's info) doesn't show all the info necessary. I had to manually pull the line down a little more and then it showed the "Master" and the "Output and Input" information. It was hidden there. Now it's working, thanks!