How to use orientation constraints in moveit?

edit

For a box picking task with moveit, I want to add an tilt to prevent losing the content of the Box. (Like moving a filled glass of water) Therefore I added an OrientationConstraint in the Move Group Python Interface:

    constraint = Constraints()
    constraint.name = "tilt constraint"
    tilt_constraint = OrientationConstraint()
    # 'base_link' is equal to the world link
    tilt_constraint.header.frame_id = "base_link"
    # The link that must be oriented upwards
    tilt_constraint.link_name = "box_gripper_link"
    tilt_constraint.orientation = Quaternion(0.5, 0.5, 0.5, 0.5)
    # Allow rotation of 45 degrees around the x and y axis
    tilt_constraint.absolute_x_axis_tolerance = 0.45 #Allow max rotation of 45 degrees
    tilt_constraint.absolute_y_axis_tolerance = 3.6 #Allow max rotation of 360 degrees
    tilt_constraint.absolute_z_axis_tolerance = 0.45 #Allow max rotation of 45 degrees
    # The tilt constraint is the only constraint
    tilt_constraint.weight = 1
    constraint.orientation_constraints = [tilt_constraint]
    self.robot_controller.move_group.set_path_constraints(constraint)

My Problem here is, that the path planner is partly completely ignoring the constraint. I am also not sure whether radians are the unit of the axis_tolerance.

Any ideas what am I doing wrong, or where the mistake could be?

Thanks in advance.

Addition: Picture of the planning scene with relevant frames (I don't have the permissions to upload a file): https://ibb.co/yXCvxXw