[Unexpected behavior]dof fetched from acquire_dof_force_tensor() and the dof set by set_dof_position_target_tensor() shrinked (not controller's delay)

why the dof state fetched from acquire_dof_force_tensor() and the dof position set by set_dof_position_target_tensor() seems different ( I knew thatthe dof position control use pd controller that will cause a delay on postion, however in my situation it seems the input of the dof has a different scale [like i want the dof vary from 0 to 90 degree but in simulation interface i can see that the joint only revolute about 30 defree])

here is the result i plot


the “:” is the input desired joint position to set_dof_position_target_tensor
and the “-.” is the output get from the acquire_dof_force_tensor