Observe a few guidelines to ensure correct surface location.
Surfaces in Autodesk Civil 3D are defined by points, breaklines, gradings, and other components. These components appear in the surface definition as surface operations, and are listed on the Definition tab in the Surface Properties dialog box.
When a surface is copied in Autodesk Civil 3D using a WBLOCK/INSERT operation, some of the defining entities for the surface are also copied, creating separate instances of these entities. For example, for a surface that is built by adding a point file and breaklines, the WBLOCK operation makes a copy of the breaklines but not the point file. During a subsequent INSERT operation, the copied objects (the surface and the breaklines in this instance) are automatically translated (moved) by AutoCAD to the new location. The new surface definition is updated to indicate that it is built from these translated entities, and then moved. If we rebuild the new surface at this point, it "jumps" from its current location to a different position. This double jump occurs because the copied defining entities for the new surface are already translated. When the translate operation for the surface (added by the copy operation) is executed, it makes the surface move again.
To avoid the double jump, the base point used for both WBLOCK and INSERT should be the same. The easiest way to do this is to use (0, 0, 0) for both operations.
When a surface is copied by selecting the surface and using the AutoCAD COPY command, the defining entities are not copied, and do not show up as separate instances in the definition of the new surface.
The manner in which these two different copying operations (WBLOCK/INSERT and COPY) are executed results in a significant difference in behavior: surfaces copied with the COPY command react to changes in the original data, but those copied using WBLOCK/INSERT do not. This difference exists because WBLOCK/INSERT makes new instances of the defining entities, while the COPY command retains the original objects in the surface definition.
Clipboard copy and paste operations (Ctrl-C, Ctrl-V) also follow the WBLOCK/INSERT logic. The copy operation actually runs a WBLOCK command in the background (writing the block to a temporary file, and placing the name of the file on the clipboard), while paste does what the INSERT operation would do. However, the base point location for WBLOCK in this case defaults to the lower left corner of the selected entities. So in order for the paste operation to avoid the double jump, you have to specify this location as the insertion point of the pasted entities. Since you do not know this computed location, the copy/paste operation typically results in a double jump, so it should not be used to copy a surface to the same or another drawing.
In summary, when you need to copy surface objects, and you want to include one or more defining objects in the current drawing (that AutoCAD will automatically translate), use (0,0,0) as the base point for the copy and paste operations. The following notes outline the recommended practices for common usage scenarios:
To copy a surface within the current drawing and have it react to changes in original data
To make a separate working copy of a surface in the same drawing (for example, to compare scenarios)
To move a surface to another drawing (for example, to reduce clutter)
NOTE: The following practices are generally NOT recommended: