For more information regarding what the killswitch does, see Does Vilfo have a killswitch?
Enable or disable the killswitch

Go to Settings ➝ OpenVPN
Locate Killswitch
Select Enabled or Disabled depending on whether you want to use the Killswitch feature or not.
Press Update
Vilfo has the killswitch feature activated by default. The setting you select here affects all of your VPN-connected groups.
We recommend you leave it enabled.