Group policies are not applied in Hyper-V environment.

Hello friends! I'm digging into GPOs here and already have some problems. I've got the active directory in entirely virtual space here - all machines are running by Hyper-V. What I've got here: Windows Sever 2012 R2, Windows 8 Pro and Windows 7 Pro (Hyper-V itself is running on Windows 10 Educational (all the rest are educational licences too)). The AD works fine. I decided to test the GPO to remove the clock from notification area first.
So it didn't work. I've made a ping from server to client and vice versa and one of them didn't work. I switched the firewalls off everywhere and then pings finally worked. But GPOs didn't work anyway. I used GPUPDATE command on the host in question (Win 8 here) and it didn't work, even when i run PowerShell in administrator mode. I'm not a PRO, so i can't find where is the problem. Sorry if this has been questioned may times.
So it didn't work. I've made a ping from server to client and vice versa and one of them didn't work. I switched the firewalls off everywhere and then pings finally worked. But GPOs didn't work anyway. I used GPUPDATE command on the host in question (Win 8 here) and it didn't work, even when i run PowerShell in administrator mode. I'm not a PRO, so i can't find where is the problem. Sorry if this has been questioned may times.

Comments
Anderson
"Everything that has a beginning has an end"
I found some policies not working when applied as user policies, but they did work when I applied them to the computer. I think I read somewhere that
the computer policy overrides user policy if they happen to conflict.
Anderson
"Everything that has a beginning has an end"
This is where the GPO was linked:
Or maybe it's because of this?:
To be honest, i have no clue why authenticated users are listed twice. However, in the Delegation window is always Read:
Anderson
"Everything that has a beginning has an end"