In most cases, you will got an issue as subject in your Windows domain environment. Even when you added the respective user into either to Remote Desktop Users or Administrator. There is no something wrong, indeed. All you have to do is only to uncheck following option in your ADUC (Active Directory Users & Groups). Select the user/group you want to allow the RDP and right click and choose properties.
Open tab Terminal Services Profile, then uncheck “Deny the user pemission…”
Please try again and you just successfully login to expected server without any issue anymore.
Hope this helps.