When I want to delete all constraints, I use Select->Selection Filters, and then make sure only "Sketch Geometry Constraint" is selected. Then I draw a box around everything and press delete.
Expected behavior: "Fixed" constraints will be selected and removed.
Current behavior: "Fixed" constraints are not selected and are not removed.
Also, currently selecting a point that is fixed does not light up anything to say that it is fixed. That makes turning off fixed kind of a guessing game.