Good extension, but I confirm the bug reported by another user. If I close Firefox (Ubuntu snap) with the VPN connected and shut down my computer, at restart when I launch Firefox there's a notifiation indicating that the VPN is connected but the browser cannot reach any website and the extensions seems broken (blank menu on icon click). The only way to retrieve a working Firefox situation is to unistall the extension (if only disabled, Firefox stops working when reenabled).