Why doesn't group policy closure work on a group?

Question

Windows

Good afternoon.
Can someone give me an idea why group policy closure doesn't work, or maybe I don't fully understand how it works. The essence of the task was:
- For all computers in the domain, put down a timeout for turning on the screen saver and enabling password entry.
In the domain, all machines are located in ou Computers, and there they are already divided into their ou (common machines, IT department, servers, etc.). Decided to make through closing of group policy on itself. It is necessary that this policy does not apply to terminals and a couple of working machines. I created a group into which I threw all the necessary machines. Then I created a group policy, turned on the screen saver timeout and password in the user settings, turned on the policy loopback option in the computer settings. I linked the policy to the root ou Computers, and removed the domain computers in the delegation, added my created group with the necessary computers, set them to read and apply, and left the reading and application for authenticated users. The policy is applied to all computers, as if there were no lock flag and restrictions on the group specified in it.
PS: I don't use the WMI filter.