There are two ways to update the client GPO on Windows 10. The old fashion
gpupdate /force on the command prompt or by running this new power-shell command
Invoke-GPUpdate from Server 2012. Either way both commands work.
You can run the gpupdate/force command on power-shell as well:

The advantage of the new Powershell command is that you can update a remote computer.
PS C:> Invoke-GPUpdate -computer remote-computername - Replace the remote-computer-name with a correct remote computer.
Add this parameter to make the changes to take affect right away:
Invoke-GpUpdate -Computer pc1 -RandomDelayInMinutes 0 -Force