This is also evident in severely diminished DC charging speeds the one time I did a full DC recharge from about 12% to 90% SOC on a 50kW ChargePoint charger.
I expected it to hum along at close to 50kW (or whatever the max supported by my 24kWh Leaf) until it got to around 80%, then decrease the power logarithmically-ish until it trickled to full. Instead, it rose to about 35kW for a minute or so, and immediately started the logarithmic-ish throttling as shown below:
Contrast this to when I charge at 6.6kW (from aobut 30% to full) and it follows my expectations:
So this adds to the growing set of evidence that my issue is caused by one or more bad cells. Can't wait to get at this with Leaf Spy Pro.
I've noticed that the car always charges in about 60% of its estimated time. That's also explained by the bad cells' reduced capacity; they fill first spike voltage once full, making the car think it's at full SOC.