My VPN was active over my mobile data connection, however when I connected to a WiFi network (requiring a username/password), the VPN didn't transition to the WiFi and the mobile data connection appeared to remain active. When I set
Data connection to off under
Mobile+SIM future connections (e.g. bing search) didn't seem to work at all.
Perhaps the WiFi network's connection was too poor (only 1 bar) - but will a Windows Phone 8 auto-transition the VPN from mobile data to WiFi?