Insert knot isn't working, or is it me?

Whenever I try the insertknot command, I select a curve, and add a point. But when I turn on pints, the new knot isn’t there. Same with control points. Am I doing something wrong?

It works fine here for me.
I drew a degree three wiggly curve, selected it, then turn points on.
Then I ran InsertKnot, selected the curve and then placed two more knots.
The curve and control points updated as expected.

What are you doing differently?

The same. Not sure why it doesn’t work.
Also possibly related, should i be able to align knots/control points? If I select some, they won’t move if I use the align command.