WMS policy's having no effect on 5070 clients

I'm testing a WMS setup with some 5070 client with a mixture of Windows 10 IoT Enterprise (10.0.14393) and Windows 10 IoT Enterprise (10.0.17763).

I have created a group and added the devices to that group.

When i create a policy, even something as simple as setting a back group, the policy says it is successfully deployed.

But there isn't any change on the 5070 at all.

I'm not sure if I'm missing something , it just doesn't work or its buggy as anything.

Here is an upload of the wall paper file in WMS


Here is a grab of the policy

this shows the job ran and the policy was successfully sent to the 5070

if i look at the device details it says

But on the device there is nothing.
no wallpaper.

i have tried with various settings and none of them seem to take any effect on the device itself.
So i'm resorting to testing with a simple policy in the first instance.