Golf 4 ATD fuel consumption display

hello,

I'm having a problem with my Golf 4. The fuel consumption display shows very high values when the engine is idling. It starts at 8-9 liters per 100 kilometers, then shows 20 liters per 100 kilometers after 5 minutes of idling, and 30 liters per 100 kilometers after 15 minutes.
Since then, I've also noticed white smoke. The fuel consumption display shows completely normal values.
The measured values and actual consumption are also normal.
Water level is at its maximum, so no water consumption is occurring.

Do you perhaps have an explanation for that?

Best regards.
ristici

Estimate:

The device measures average consumption, not instantaneous consumption.

The car is stationary, the wheels are not turning, but the engine is running. Therefore, the average fuel consumption naturally increases constantly, because you're wasting fuel without the car moving.

In my opinion, the two things have absolutely nothing to do with each other.

No, it's about the current consumption, and the white smoke is getting worse, especially when the engine is cold.
"The error memory shows no codes, the measured values are okay, the coolant level is okay, the performance is okay, and the real-world fuel consumption is also okay. The mass airflow sensor is working properly, the temperature sensor is good, and the fuel injectors are also good."

I don't know what else needs to be checked.

Best regards.