Tobias, big thanks about your reply. I'd be very pleasedĀ if you have a look why it doesn't work for me.
Via NetworkManager-Strongswan (doesn't work): https://gist.github.com/kuraga/18bb0b6746acc958de343cfa9ba8ce4f Without NetworkManager (works): https://gist.github.com/kuraga/535c803855a4b159796840c0736d2e02 (I follow strictly https://nordvpn.com/ru/tutorials/linux/ikev2ipsec/ but the only place they differ I think is "leftauth=eap-mschapv2".) Thanks one more time! Regards, Alexander Kurakin