Thank you for your answers.
The described problem concerns the model Elektrolux ERD 2343 (two doors - separate upper freezer).
You write logically (from the point of view of physics), but I look at it differently. Not from the point of view of the service defending the producer, but the consumer. When something crackles and shoots after 7 months in the car, we have doubts, isn't it true? And how to explain the fact that the 7-month refrigerator was OK in this respect

According to me (the consumer), something started to happen inside, maybe it went wrong. Maybe some process occurred too quickly (the name is "aging" of the equipment), maybe the wrong components were used in this production batch, maybe a cooperator collapsed, etc. after a few years, he had to issue a helmet again, and he did not enjoy decades of trouble-free equipment).
In addition, I have another fundamental doubt that occurs from the very beginning of using this refrigerator and concerns the temperature in the cooling section. This model has a thermostat graduated from 0 to 6. In the manual, the manufacturer recommends as
optimal setting the thermostat to the "2-3" position (approx. 40-50% of "power") and then the temperature should be below -18 oC in the freezer and +5 oC in the refrigerator. Experimentally, I put 3 thermometers in the refrigerator and I have readings: at position "3" -18 / -22 oC (freezer) and + 8 to 12 oC (in the refrigerator upper and lower shelf) - I think it is
TOO WARM By setting the thermostat to pos. "6" readings -25 / -28 oC and + 4/8 oC.
Conditions in the kitchen: temperature +18/19 oC, refrigerator 3-4 cm from the wall (everything according to the instructions). To sum up:
I feel a "deficit" of cold in the refrigerator part. Generally, on many food products we can read that it is recommended to store them at a temperature of 1 to 6 oC. I cannot get such a temperature at home, even on position "6", ie 100% "power". So the conclusion is: does this equipment meet the requirements for refrigerators? In the manual, the manufacturer warned that position "6" is used to quickly freeze a "large load" and should not be set for too long, because the temperature may drop below 0 ° C in the cooling section and the products may be frozen. In my opinion, the producer did not keep his promise and misled me

I do not have equipment that meets the requirements of "civilization" and food producers.
IS IT A DEFECT AND DOES IT NOT HAVE IT
PS My old "Silesia" fridge (18-20 years old) was able to freeze cold meats under the freezer at 70% power (it was about - 2 oC). It worked without failures all the time, but after the renovation of the kitchen it was too ugly - we gave it to the "needy".