I am having a bizarre problem since updating to iOS 10 using astropad, apple pencil and the latest version of illustrator CC. My brush strokes, now only register every-other stroke. Meaning to make a brush stroke, I must first tap the screen, then draw the stroke, tap the screen, draw the stroke. If I don't tap first, the purple line traces my pen, but the stroke does not appear on illustrator. I am also using Sierra beta. Any thoughts?