Make sure the user you try to use has “Include inheritable permissions from this object’s paret” checked on the Active Directory user’s permissions.
Open “Active Directory Users and Computers” then. Go to “View” and make sure “Advanced Features” is checked, if it isn’t – check it. Find the problematic user and open its “Properties” (right click –> Properties). Go to the “Security” tab and click on the “Advanced” button.
Verify that the “Include inheritable permissions from this object’s parent” checkbox is checked. If it is, you may try to reset the user’s permissions by clicking on the “Restore defaults” button.