Why Network Manager is not available to new user accounts in 16.04? Why nm-applet does not start for new users?

Network Manager (nm-applet) is not available in the panel for new user accounts, and manually running nm-applet does not start the network manager.

I needed to create 2 accounts for different users, and gave them administrator level and also permission to create and connect to networks.
But nm-applet does not autostart and do not launches running from the terminal. It simply won't say anything after running nm-applet. There's no simple way to make it run.

I followed the workarounds for previous releases, such:

• making sure that "indicator plugin" is active on the panel,


• and, in Application Autostart tab of "session and startup"
  
  
  
  • "network" is configured to autostart,
  
  
  • "Indicator Application" are configured to not autostart,
  
  
  • added nm-applet command for it to autostart.
  
  

As a system administrator I can't figure out what else should a user do to access networking.

Network Manager is running for the default (1000) user. (BTW default user is connecting to WI-FI without specific permission to do it.)
The new users accounts were given users ID below 1000 for they to not appear on login window.

NOTE: We are running "ubuntu desktop" sessions, after installing "ubuntu studio" packages, on a fresh install of Ubuntu 16.04 LTS. New users are being created on "users and gropus" option in the System category of the Whisker menu.