We have a global GPO that grants Local Admin permission to "Domain Users" via Restricted Groups. I was asked to remove the Local Admin to few users by applying a security filter on their computers. All the approaches I tried didn't work. do you have any idea ?
Any GPO that target USER but got Computer setting must have the local loopback processing mode setting enabled.
Computer Configuration\Administrative Templates\System\Group Policy
Merge indicates that the user policies defined in the computer's Group Policy objects and the user policies normally applied to the user are combined. If the policy settings conflict, the user policies in the computer's Group Policy objects take precedence over the user's normal policies.
Check the order of the GPO too, as of course both of your GPO apply to him (domain user + the gpo with him).