The battery state monitoring takes place while the car is off and the battery is not being charged by the alternator (or inverter in the case of the leaf), so if the tender is hooked up directly to the battery terminals, then those readings would be off. Don't have docs on the leaf but here's...
Not claiming to know that this is case with the leaf, however, Other car companies (e.g. BMW) have modified the way their batteries are charged in the past 10 years or so. Instead of just having the the alternator charge at whatever the VR is set to, they will adjust charging voltage/amperage...
I have a simliar issue with my 2016 SV. NIssanConnect never gets info from the Car, despite the TCU reporting that it successfully connected and being able to download feeds. I've had a ticket open with Nissan North America for over a month, since a couple of days after purchase. Initially the...