Asus vp28uqg freesync not working

[cromkiller12]

I have a asus vp28uqg with a amd rx 480 4gb when I try to enable freesync on my monitor its grayed out. When i'm on amd radeon settings it says amd freesync is on i'm confused how do I know if its working or not?

 

[Glenwing]

You may need to enable FreeSync in the monitor's menu.