I draw a spline using the “control”-option for setting spline points. But adding a new spline point (as described) by selecting the spline and then press with the pencil didn’t work - doesn’t matter whether I did on the spline or somewhere outside.
When I use the “fix”-option for creating a spline and then add a new spline point, it works.
Is it a bug in the program? Or do I do something wrong?
It only works for fit point splines
Thanks!
I guessed 
But one never knows 