I think you have to dig into the manual a bit and look at the interface in Kontakt.
The library likely has different articulations. They could be triggered based on velocity, or key switches, or maybe you have chosen an articulation that adds trills at the end of a sustained note.
Could you be playing on multiple channels and triggering different articulations that way?
yes, or in my case I was taking a multi in (Oakland horns) and changing all incomming midi channels to 1 since that’s how I fundimentally use GP… and their key-switch positions which change articulations overlap the note range of the different instruments so depending on the notes I played I was changing articulations for different horns.
I’m new to playing horns on keys so I didn’t understand the concept of keyswitches.
Big Fish Audio support called me back and had me reveal the keyboard GUI which shows in red the keyswitch keys for each instrument… and they explained that this isn’t exactly ment to be used live but that I can experiment with limiting my play range or the number of instrumetns as needed, etc…
But I could probably, using GP, remap the keyswitch notes all to a common out of the way octive (or another controller?) so I can still play with a stack of horns to get the sound I want and still change articulations. Will take some work but would likely be the solution.