Grove GSR Sensor

Hello,

I just bought a new Grove GSR sensor and I’m trying to put it into operation following the instructions in the wiki. (Grove - GSR Sensor | Seeed Studio Wiki)

However, I can only set the minimum adjustable resistance to 540 and not to the required 512.

Is this a known problem, does anyone know how to solve it?
And whether this has an effect on the accuracy of the measurement?

Thank you very much!