Hi Ludwig and thank for the answer.
What is confusing is that it’s not happen all the time. Your little trick ll be usefull! Ill try it probably tonight.
I’ve also noticed that sometimes i 'm hearing some notes, i can even see it on the track midi event, but i can’t see it anymore (and i can’t edit it) once i’ve opened the key editor. That’s particuliarly the case since i’ve changed my usual drumkit (which were rock kit 1) into AMdrum kit 1 (my original midi event was created with the rock kit1). Probably something already reported.
Anyway, the AMdrum kit kill and sound more natural than the olders one. Great job!!