I've been having same issue it seems like some shadow banning is happening.
The way I got around is to download OpenVPN GUI and just put the NordVPN server config in the config folder and connect, actually it's faster to connect this way than the app which shows how bloated the NordVPN app is for it's minimalistic purpose it serves.
Check out these two links
https://nordvpn.com/...ows-10/openvpn/
https://nordvpn.com/servers/tools/