The coffee version has a significant increase in precision and resolution than the other versions. The amount of dissolved solids in coffee is much lower than the amount of sugar in fruit or honey, and therefore the much wider range available on the other versions is not necessary when testing coffee.
There are many possible reasons for this. You should check the following tips: Conduct calibration before testing. Clean the sample dish thoroughly and make sure there is no liquid left in the sample dish. The readings may jump while the liquid is cooling down, wait till the temperature of the liquid comes to stabilized. Insoluble substances in turbid liquids affect the measurement results after precipitation.
We won't use your location info indeed, but Bluetooth permission is contained within Location permission. So if permission is not granted, the device will not be able to connect with the APP.