javacafevn

Yes, it works with sudo, even without sudo. But wlan0 filter is disabled if the app is launched directly from menu.

Dear, "iw dev" works. It shows wlan0 information. It seems I'm the only one facing the problem. Or XFCE is the cause?

It seems you need a VPN client with TUN mode. Then you can use TUN as the internet interface. It's my case.