I just had this problem when my 12 volt battery died (pretty new battery) while plugged into my l2 charger for about a day. I ended up jumping it with a battery charger which got it working again but with i-key error. Disconnecting the negative terminal and reconnecting it fixed it. Hope this...
If you can log into the portal website and not into the new ev app try logging into the portal and changing your password to something shorter than whatever it was before. After I did this I could get into the android app.
I remember seeing a screenshot of the website saying carwings will be update to the new nissan connect ev app. They need to make this less confusing though theres 2 nissan connect apps on the playstore now and with ev there will be 3...