"Stairs require no more than two boundaries" Anyone seen this before? Yes?

I get this almost every time I try to make a stair that is not 100% straight and has more than one run.

As an example I was trying to make this stair:

So I went ahead and created 3 runs. Note the way the boundaries are not really what I want:

So I tried:

• moving the boundaries one by one: error
• deleting the ones that are wrong and redrawing them: error
• deleting all boundaries and drawing them by hand: error

What  finally worked was tab-selecting the entire boundary-line and moving the handle.

The issue with this is af course that it makes it impossible to make rounded boundaries, but at least I got this stair done.

Now if I could only make Revit create a monolithic stair like this.