This appears to be a new issue for me in C8P 8.020
Trying to split a note in the MIDI key editor using alt-click (the scissors appear) sometimes (often in fact) duplicates the note instead of splitting it. Of course we also use Alt-Grab to duplicate a note, so the difference is subtle, but I’m being careful not to move the note after clicking on it and rarely if ever had any difficulty before getting the correct behaviour. Now it’s really very hard to split a note this way for me.
Anyone else notice this? I don’t use MIDI editing that often so it might have been like this for some time.