My laptop's DroboFS /Volume has two TimeMachine directories - is this normal?

My Drobo has been acting erratically lately with one of my Macs that use it as a TimeMachine backup - the one machine can never seem to find the Drobo to perform the backup whereas the other three machines can.

Even when I’m disconnected from the network, “DroboFS” shows up as a /Volume - perhaps due to DDAssist loading as a Login Item in Users & Groups? So I can browse the folder structure in Terminal of even a disconnected Drobo?

Anyway, I was looking into the Drobo’s file structure and noted that there are two TimeMachine directories in two different higher-level directories named “1” and “3”. Is this normal?

Just to clarify:

      \ tdd12xxxx17
            \ 1
                  \ Drobo
                  \ DroboBackup
                  \ TimeMachine
                  \ Video
            \ 3
                  \ TimeMachine

Notably, when I browse the “DroboFS” folder on another Mac on the network, only the “1” folder shows up. And on another, even though DDAssist loads, I do not see the “DroboFS” Volume at all…

Anyway - on the machine with the two folders “1” and “3”:
Both “TimeMachine” folders appear to be empty except for a “.VolumeIcon.icns” file … But like I said, several machines have been able to back up to it normally.

Is this a normal file structure? I’m inclined to wipe the Drobo and start from scratch and hope that all the machines backup normally, not just a few. What causes “DroboFS” to show up in the /Volumes directory at all if the machine is disconnected from the network? Can I safely remove the “DroboFS” directory and force it to rebuild (and hopefully lose the “3” folder to clean it up)?

When I do mount the Drobo, I don’t see these “tdd12xxx…” folders and “1” and “3” - just the directories I expect - namely “DroboBackup” and all its included folders. I can’t browse the “TimeMachine” folder.

Is this normal to have these two “1” and “3” directories with two “TimeMachine” folders? Is it a problem with the Drobo? Is it a problem with my laptop (since it only appears on this one machine)? More important, can I fix it?