I have a similar problem as described in this thread: https://community.cadence.com/cadence_technology_forums/f/custom-ic-design/36786/synchronous-copy-of-group-with-mpp-results-in-flattened-mpp
If I copy a group which contains an MPP, the copied group consists of the MPP (correct) and a flattened version of the MPP (wrong). The flattened version of the MPP further contains only the subpaths and subrectangles, the main layer is not present. Even more strange, the flattenend elements cannot be selected, eventhough they are present if the group members are queried via the "Edit Fig Group Properties"-Form.
Is there any workaround to this behaviour or does anyone know what is causing this?
I am using IC6.1.8.500.14.