create a project that contains group channels
save an arbitrary amount of channels including the group(s) as part of a track archive (file > export > save selected tracks),
import the archived tracks into a different project (file > import > track archive)
1/ group tracks do not retain their original channel strip settings
2/ audio tracks in the original project routed to group channels that were all saved within the track archive, are no longer correctly routed to the imported group tracks
3/ the newly imported group tracks cannot be routed into from any audio channel in the new project, existing or newly created (cubase is not seeing them as targets for sending audio to).