OceansAndEarth

I was trying to solve a spot - BB vs SB SRP.
I am using GTO+.
The flop decisions are check, bet 30% and bet 66%.
The entire decision is summarized as below -

Percent: 21.3% (bet 66%), 11.2% (bet 30%), 67.5% (check)
EV: (37.71, 33.3, 23.61)

So, what I am trying to understand is the following - why is the higher frequency line (check 67.5%) the one with least EV (23.61)?
Is it something counter-intuitive or am I missing something completely?