Comment 7 for bug 826056

@Michael Owens - your file does not contain a 3dbox - this report however, bug #826056, is specifically about 3dbox objects.

Your example 'test.svg' contains two unconnected connector lines inside the group which do relocate (aka re-route) unexpectedly when copy&pasting the group: pasting a new copy triggers a rerouting of the connectors inside the prior pasted (i.e. transformed) group, to a fixed position - likely because the connectors have loose ends, and there is no information how to reroute (aka layout) them correctly.

Based on the drawing content, there seems to be no compelling reason to use connector lines instead of regular paths for that specific design (connector lines cannot connect to nodes, but only to midpoint of objects), so my recommendation to avoid this specific issue with unconnected connector lines inside transformed groups is to delete the those two in the original group and redraw them with regular path tools (pen, or pencil tool), with node snapping (nodes and handles, cusp nodes) active.

If you can't find an existing related bug report about (unconnected) connectors (inside transformed groups), consider filing your issue separately (it's not related to this bug, and requires a different solution).