DRV8899-Q1: different current draw between two drv8899 at same motor

Tool/software:

Hello,

I have build multiple boards with DRV8899 and if i compare them to each other with the same stepper connected, I see around 50% of current missmatch.

I am using DRV8899 without any SPI configuration, so its in its default configuration when powered.

the Voltage on the VREF Pin is 1V at both chips.

but with one DRV8899 i get around 300mA current draw.  with a different DRV8899 (but same schematic design, and also 1V VREF) i get around 180mA current draw.
I am using the exact same Stepper motor for that test.

does anyone have some hints where the difference in the current draw might come from?

Fabian