After upgrading my Mac Pro to sierra,
when dragging a velocity marker or cmd+dragging midi note up and down ,mouse gets really laggy and erratic.
when activating Pen Tablet mode, i can edit the velocity normally, but fine-tuning a parameter while holding shift is unusabled
It never happens with Live 9, very weird
I'm using mac pro 5.1, High sierra, Live 10.1.18, Live 9.7.7, Razer Viper