Android device prompts for password when a user with full-control is granted access through a share

We need to give a user access to a group of devices so we setup a group and put the new devices into that group - all devices are Androids - tablets basically. 

Then we created a new user and this user has "Share" access to this single group... full control.

When the user logs in and tries to connect to a device (can see the devices) - the device prompts for a password saying that the password is showing on the screen on the device and it must be entered. The screen doesn't show the password.

How can we setup a user that has only access to one group of devices and not have to get some password from the screen?