Dell OME displaying IP not Hostname

Hi, 

we've just added 6 R750sx ESXi hosts.

In OME , under All Devices,  all 6 are there, but 5 are listed with their hostnames and one with the IP address. It's annoying.

How can I change this. It's ok to delete and rediscover (tried that but it still comes back with its IP not hostname)

On a similar vein and probably related, when I go into Configuration > Firmware/ Driver Compliance > and look at a new Baseline only 5 of the R750sx's are listed and it's the one with its IP address that's missing from there too.

Any suggestions on how to see all 6 with their hostname?

Cheers

LT