Don't they give the battery capacity in Amp Hours like the BMW literature? That would be 60 Ah, 94 Ah, or 120 Ah. Did they make a 2018 model with a 120 Ah battery? Did they make a 2019 model with a 94 Ah battery? I thought that 2017 was the only model year where you could get two different sizes of battery: 60 BEV, 94 BEV, or 94 REX. If the battery capacity doesn't match the model year, I would be suspect of both.
Specifying the battery size in Kilowatt Hours (kWh) is a little vague because each battery had two kWh ratings: Gross (theoretical capacity) and Net (the capacity you could use without damaging the battery.
60 Ah -> 21.6 Gross kWh, 18.8 Net kWh
94 Ah -> 33.2 Gross kWh, 27.2 Net kWh
120 Ah -> 42.2 Gross kWh, 37.9 Net kWh
Sounds like you are talking about the 94 Ah and 120 Ah batteries.