The units are controlled by a sensor located in the cabinet, so the display on the screen compared to your OWN thermometer can actually vary depending on the position you place it within the fridge, the location of the cabinet sensor and how your fridge is filled with product.

Good things to know are;
1. The difference between TOP section and BOTTOM section can be about 2oC, with bottom usually the coldest. So setting at 2oC means when sensor 'feels' 2oC it turns unit off, at this point inside fridge that area will be 2oC but higher positions in fridge will be 3 or 4.

2. For more 'even' temperature you should keep the area 'in front of GRILL' on the inner back wall about 5cm free from product, allow the air to blow out the bottom and have small spaces between the product to allow to to flow to all area's of fridge.

3. Again check for ice on the rear inner wall, if evaporator has iced up you lose air flow and unit won't run at set temperature.
*Try resetting the controller parameters in case the unit wasn't done correct, see link;
https://www.bar-fridges-australia.com.au/schmick-yc-range-parameter-change-document.html