My only suggestion would be an email to
support@nordvpn.com
It seems like you have tried a similar move already with little success but they have always been very helpful to me.
I'll note that I use
then
to get things going rather than involving any other software. The nord site does include openvpn so they should have an idea how to help. Your problem is excellently documented so they have plenty to work with
The login process changed some time ago so maybe this is just hitting you now
