Remaining Battery Bars vs LEAF Spy App SOH Reading

So as I've been shopping for used LEAFs, I've been reading the state-of-health (SOH) percentages using the LEAF Spy Pro app and comparing with the remaining skinny far right battery bars (BBs) on the console. I found they don't always seem to correlate.

From what I've read, the first battery bar represents 15% capacity, each subsequent only 6.25% capacity.
(On a side note: 1 X 15% + 11 X 6.25% = only 83.75% and not 100% for all 12 battery bars -- ???)
Nevertheless, if I go with what I've been read, then:
12th BB should equal 85% SOH,
11th = 78.75%,
10th = 72.50%,
9th = 66.25%,
8th = 60.00%,
... down to
0 = 16.25%.

For the limited cars I've tested, the following shows SOH measured, battery bars observed and battery bars that should be shown:

Car A: 71%, 10, should be 9
Car B: 84%, 12, should be 11
(I will post more data as it becomes available)

So, which should I trust more when determining a used car's overall battery health-- Nissan's battery bars or the LEAF Spy Pro SOH reading ?

Thoughts?

Nissan has programmed the BMS to only "drop" bars after the internal resistance has indicated it should happen for quite a while - weeks to months. It also seems to be tied to temperature, with bars refusing to drop in Winter even when they should do so. I'd use LeafSpy over the bar reading, keeping in mind that a BMS reset can invalidate both measurements...