Can't use curvature tool in a layer above an image trace
I placed and image traced an image of line drawings of a ship. I wanted to trace some of the lines and replace some of the originals. I tried to use the curvature tool and saw blue anchor points, but no line appear. A layer was added above and I tried there, no luck. Finally, I traced to the side of the desired line and got it to work, but that's not sustainable for the whole drawing.
Why can't I use the curvature tool to trace a line drawing from an image trace in the layer below?
Thanks!
