LTC3310, 0,85V 6A power supply

Dear team,

I'm using the LTC3310 for a power supply with Vout=0,85V and Ioutmax=6A (see the scheme below).
The inductor code used is XEL4030-101ME (Coilcraft).
I calculated the feedback resistors values using the formula reported in the datasheet (page 14), with those resistors values Vout should be 0,849V but the real Vout voltage measured is 0,827V. Why there is this big difference? There are errors in the components values used?

Thanks & Best Regards,