Some backup volumes don't appear in the Finder (sidebar, nor Desktop, nor Computer)
If you created a bootable copy of Catalina, Big Sur, or Monterey in the past, and then proceed with CCC backups to that volume on Ventura without specifically using the Legacy Bootable Copy Assistant, CCC will remove the incompatible System volume from the destination. Prior to Ventura, the remaining Data volume would appear just fine on the Finder Desktop, and also in the volume list when you select "Computer" from the Finder's Go menu, but not in the sidebar. In Ventura, this volume no longer appears in any of these locations, regardless of your Finder preferences to show external volumes in the sidebar, and regardless of any attempts to drag the volume explicitly into the sidebar.
We reported this issue to Apple (FB9739492) in November 2021. Apple never replied, and only made the problem worse in Ventura. Hopefully we'll see this issue less frequently as people migrate away from legacy bootable copies of macOS.
Workaround: You can create an alias of the volume on your Desktop:
- Click "Volumes" in CCC's sidebar
- Right-click on your backup volume in CCC's sidebar and choose "Reveal in Finder"
- In the Finder, hold down Command+Option while dragging the revealed volume to your Desktop to create an alias
Solution: Erase the volume in Disk Utility and start the backup from scratch. The underlying cause of this problem is the presence of an irrevocable "Data" role applied to that volume by Apple's ASR replication utility. macOS has documented functionality to remove that role, but that functionality does not work (FB7208067, Sept 2019). Erasing the volume is the only remaining recourse.