Domain admin without local rights

[SuperCice]

Hello to everybody!

i've a strange problem on a new Proliant Dl20 gen9 server with Windows 2016 standard with desktop.

After installing Active Directory and DNS (a new normal domain and forest), domain admin losts its local right.

I cannot change logon account on many services, cannot change desktop icon, cannot access to many services (like event viewer) with access denied response, I get a rundll32.exe access denied (!!!!), Server Manager windows shows Unknown near every main server function (Windows Firewall:unknown; Windows Update:unknown ecc.) and so on. Anyway, AD and DNS seems working right.

Why this happens?  Have I miss something? I tried at least five installation with/without Intelligent Provisioning with same result. Media are original HP DVD (ROK). Same steps: installing windows, configuring network card with static ip, roles (AD+DNS) installation, post installation AD config with a simple forest and domain.

Someone does have an idea?

Thanks in advance.

Andrea