You did configure a User policy, correct?... and give it time to replicate
to other DC's.... and time for the computer to realize there's a GPO
awaiting that user. If you've done all that, and doing a gpupdate /force
/sync doesn't get the computer to apply the policy, it would sound like a
DNS issue. Ensure you're not pointing the computer to any other DNS server
other than your DC(s)
HTH
Ken