My Samsung refrigerator won’t keep the temperature I set. I set the f

My Samsung refrigerator won’t keep the temperature I set.

I set the fridge temperature to 4°C, but after some time it automatically goes back up to 9°C by itself.

The fridge can be turned on normally.

When I adjust the temperature, it changes, but later it resets to 9°C.

I’m not sure if Vacation Mode or Demo Mode is activated.

Why does it keep resetting the temperature to 9°C, and how can I fix this?