Appliaance shuts off at low temperatures
Most refrigerators cycle on and off based on the fresh foods temp. If the ambient temp is 10C and you have it set for 4C, the unit does not have to run much to satisfy the temperature control, and the temp in the freezer section will warm to + C range. (likewise, if the ambient drops to -C range, it won't mater if you set the fresh food section to +4C, it won't heat the air, and the fresh food section will eventually reach the -C ambient temp.) The only solution is to move the appliance to a warmer location or heat the room it is in. This is the only Fix-Ya for your refrigerator.