Used the NM applet to access Gnome Settings for network and added (Open)VPN via
import from file. Then verified via VPN settings that automatic connection was
checked.

However, only the wired network does connect automatic during boot up, which is
verified via the NM network icon menu at GDM login. After login to a Gnome
session, the VPN does still not auto-connected. Have to connect i manual from
the NM applet menu, and then VPN connect and gets its own separate icon. If VPN
is not manually connected relative short time after login, an Administrator
Authentiation is required.  

(On 42.3 Gnome there is a somewhat different behaviour, as neither wired
Ethernet nor VPN auto-connect when VPN is configured to auto-connect. Manual
connecting Ethernet here also does connect VPN, and they get one single, common
icon).

Any log files of interest here?