Scenario : 1) Launch AirVPN (network lock mode) 2) Launch Firefox 3) Browse any website and leave Firefox opened 4) Close AirVPN the "clean" way (AirVPN menu > Exit) : DNS settings are back to normal (I verified this) 5) Try to browse some other websites from the previously opened Firefox window : webpages won't load (blank page) 6) Close Firefox completely 7) Re-launch Firefox : this time webpages are loading normally Why do I have to restart Firefox once I'm done with AirVPN client ? BTW, if I launch another browser (IE, Vivaldi or whatever) at step 5 webpages are loading normally