I determined a likely cause for this issue today - if the VMs have the same uuid.bios parameters they will appear as per your screenshot as vSAN Health/Monitoring has dependencies on this variable and thinks that the Objects associated with all subsequent VMs with identical parameters belong to the initial VM.
On vSAN or otherwise (unless some element strictly relies on it), best practice is to deploy/clone/create VMs with unique IDs - this can be configured based on the solution (e.g. vCloud Director), in the vmx configuration and other ways. But in your case if you just want this to display properly then manually change the uuid.bios parameters of the VMs vmx to be unique (or re-deploy/clone the VMs putting in place measures that they are deployed with unique uuid.bios).
Thank you Bob. I just found this same answer out yesterday! Yes, it was two VM's with duplicate bios.uuid's.
In the process of deploying/testing Veeam Backup and Recovery, this issue came to light again as it barks if dup uuid's are present as well.
Problem solved. Thank you again.