@FredB
I have the same problem.
It looks like the key editor limits itself to the range of notes available in the loaded instrument. The previous drums had a much larger range of notes. The AM drums have a smaller range so any notes out of range can’t be seen/edited.
Can I just add that the key editor limiting is wrong also. The range of the AM drums is C1-D#2, D# is the ride, but the key editor only goes to D2 so if you’re using the kick and ride you have to scroll the window up and down to edit. Very irritating.