MAX20361 not harvesting below 1V

Hello, 

I'm using the MAX20361 to charge the Li-ion battery (nominal 3.7V) of a portable device from a small solar panel (<2cm^2 area), and I'm also storing the Harvest Count and VOC every minute. Tper/Tmeas are default so 256 and 50ms. When I plot the harvest counter vs. the open circuit voltage, I see that the harvester doesn't really seem to be going at voltages <1V. 

This is unexpected because the datasheet notes that the minumum harvest voltage is 225mV. Once it's encapsulated in the device, I cannot measure the power directly, but for the solar panel to reach even ~500mV should be enough input power to be harvesting, yet nothing is happening. What units (uA, uW) is the harvest counter in? And is it possible that the chip is harvesting at such low rates that we're just not seeing it?