Hi!
I think what you're seeing may be stale entries in the XAPI database, ghost records that can survive upgrades or host reconfigurations.
From what I've read, xe vm-destroy uuid=<vm-uuid> removes the record without touching any storage, which seems like what you need here; the xe CLI reference confirms storage is left intact.
I think you can get the UUID first with xe vm-list name-label="Before Ubuntu Update" (replacing the name with whichever one you're after).
I'm not entirely sure why xsconsole would show them but XO wouldn't, so if the VMs don't turn up in xe vm-list, it might be worth a mention to Team-XAPI-Network, they'll know the right way to dig into XAPI state.
