Ok, I've taken a look at the savefile, and as it turns out, it's actually correct.
The reason is that by not betting, OOP is missing out on a huge bluffing opportunity.
The situation on the river is that the pot is 20, and the remaining stacks are 2.
Villain's range is polarized between having the nuts and holding air.
See below for the equity distribution of his range.
As it turns out, even when receiving odds of 11:1, IP is still folding 90% of the time.
Because of this, 76 should be bet here for an EV of 21.47.
The EV of checking is only 2.97.