I've encountered a similar problem in macOS Ventura where the Desktop no longer displays all of the mounted devices and Finder does not display them in it's sidebar. The mounted devices that are not displayed are CCC backup copies of the Macintosh HD volume. All of the devices that are not displayed are APFS devices containing macOS Monterey backups of the Macintosh HD system disk. I haven't done any CCC backups of Macintosh HD after updating to macOS Ventura.
Disk Utility displays the devices and notes that they are mounted. Currently, if I attempt to dismount the devices in Disk Utility, it will initially complain that the devices/volumes are in use until I dismount the container.
The Senior Advisor at Apple Support that I spoke with was unable to provide a solution to this problem.