Autodesk's Jeff Bartels walks through a trick to employ the Toggle Label Pin tool and a tweak to the Label leader to fix a label location for a Structure in Civil 3D.
From the Jeff Bartels YouTube Channel.
and the Civil Immersion blog.
You have to do this trick a couple of times to learn how the mechanics work. This is a workaround for a common compliant about the Structure Label Style in the Dragged State.
Seems silly to have to add the leader vertex, but it forces Civil 3D to obey when coupled with a Label Toogle Pin property assigned to a specific Label.
As Jeff points out in the video, you can employ the Toogle Pin Tool to Labels in other views.