You have found you are getting unknown error (0x80072f05) when changing properties within Windows Virtual Machine Manager.
Go to mmc.msc and add the certificate store for the local machine. Check on the personal store and you should see the certificate has expired.
First run a test-netconnection fqdn of vmm server -port 5985
This should show pass.
$credential = get-credential
Get-scvmmmanagedcomputer -computername “fqdn of vmm server” | register-scvmmmanagedcomputer -credential $credential
once the above has been run you will get:
in the event logs.