Scale actions scale from their governing parameter's end point when set to Dependent. When set to Independent, a scale action base point appears when the action is selected and that base point can be moved to any desired loaction (the same is true for rotate actions). The scale action will then scale from that base point. To fix your block select the scale action for the arc that is scaling incorrectly. Go to Properties and change Base Type to independent. Move the scale action's base point from the base point of Distance1 to the centermost end point of the arc that is scaling incorrectly. See attached.
