The only info I could find on any changes with the '17 AWD that might possibly explain it:
"There is, for the all-wheel drive versions of the compact crossover, the i-ACTIV AWD system that uses sensors to calculate—two processors are used, operating at more than 200 calculations per second--27 factors that determine where torque should go, with as much as 50 percent of the power (the 2.5-liter engine provides 187 hp, which is an increase of 3 hp from the previous model) to the rear wheels. The system in the 2017 model uses tandem ball bearings in the rear differential that (1) provide greater strength under load, (2) result in 30 percent reduced friction in the rear diff, and (3) allow a 2 percent improvement in real-world fuel economy."
Something is different since the FWD kept the same 0-60 with more weight and the AWD lost 3-5 tenths with more weight.