Before I posted this I did search for this issue both here and google.
The issue I am seeing is with 10.13.4 systems. After the upgrade my users are being prompted that a system with the same name exists on the network. I have checked DNS and DHCP for duplicate systems and none exist.
The wildcard here is the number after the computer name increments up really high and really fast.
The number also only seems to only append the computer name not the local host name or dns name.
Has anyone else seen this or similar and if you have is it fixed?