Here are the things to check when you have 2 instruments that read differently.
1) Standardize and read the green check tile on both instruments. If they pass, then the sensors are operating correctly.
2) Check that you have selected the same color scale and illuminant/observer for both instruments. This is typically CIE Lab or Hunter Lab and D65/10 or C/2. They must match on both instruments
3) Make sure you are presenting the samples at the same height and in the same manner of placement. The distance is given with the reading or you can go to Diagnostics/Distance sensor to read the distance from the sensor to the sample being measured. Both samples need to be arranged the same way, whether poured, stacked, or crushed.
4) Check that the measurements are at the same location on the samples, This is determined by the location of the sensor over the sample. Use the horizontal arm to adjust the white spot from the center to the outside of the sample pan and set it is the same position for both. The white spot is the measurement area, and the red spot is the height measurement.