Windows Defender ATP Policy doesn't apply to all clients

I've setup a new Windows Defender ATP Policy and deploy it to 4 clients Yesterday but it showing only on 2 clients in the Configuration Manager "Configuration" tab under control panel of the client.

Why the policy don't apply to the other 2 clients from Yesterday? I have run the Machine Policy action without success. In the monitoring this clients appear on "Unknown" tab.

There is a log I can check for errors? Any ideas?

Thank you.