Enabling vTPM on Hyper-V VM

I am attempting to enable the virtual TPM on a Hyper-V VM, when enabled I attempt to start the VM and am given the error:

Start-VM : 'KF-WIN10' failed to start.
'KF-WIN10' could not initialize.'KF-WIN10' failed to start. (Virtual machine ID 9E926667-9C80-4D83-929A-61D5B002AC74)
'KF-WIN10' failed to start worker process: The computed authentication tag did not match the input authentication tag.
(0xC000A002). (Virtual machine ID 9E926667-9C80-4D83-929A-61D5B002AC74)
'KF-WIN10' could not initialize. (Virtual machine ID 9E926667-9C80-4D83-929A-61D5B002AC74)

I have a Host Guardian Service running which is the Key Protector, the cmdlets I am using are:

$VM = Get-VM -VMName KF-WIN10
Enable-VMTPM -VM $VM
$Owner = Get-HgsGuardian -Name 'STSHGSGuardian';
$kp = New-HgsKeyProtector -Owner $Owner -AllowUntrustedRoot;
Set-VMKeyProtector -VM $VM -KeyProtector $kp.RawData
Start-VM -VM $VM

I am running Hyper-V on Windows 10 1809.

Cheers