On OSX 12.6.6 on latest Dorico 5.0.10, I’m having trouble drawing MIDI cc in the key editors.
I can draw a change to an existing curve once, but then I start getting this weird behavior where hovering the mouse over the key editor draws a whole bunch of dots, but doesn’t actually persist / update the curve (hard to explain):
The problem, I think, is that Dorico is losing the mouse release, so you end up continuously editing the same region. This is the same problem discussed e.g. here: