Apple Configurator settings have no effect

We have a bunch of iPhone 6s which I want to prevent from talking to unauthorized PCs and Macs when connected via USB.

I have connected one of them to a Mac, opened Apple Configurator, and set up a profile with the options I require (enabling supervision and unticking "Allow devices to connect to other Macs").

However this seems to be being ignored. When I connect the phone to another computer it is quite happy to talk to it, it shows up in iTunes, etc. and it allows me to use options that I thought I had blocked, such as Siri.

Suggestions welcome! Thank