I have a question understanding app policies.

I created an app policy including an apk file with deployment Mandatory and a config (app source = Enterprise). 
On the device under configuration I see that the policy is asigned.

My understanding was, that the app will be automatically installed with the app policy set... but it doesn't :-(.

I than tried to install the app via package and only set the config via policy. Result app installed config doesn't.

Am I doing anything wrong?