Thank you for clarifying. Indeed that is the pressure in the intake manifold. Not the boost pressure. So the boost pressure is 0.2bar in this case.
It seems that the system is controlling the intake manifold pressure, not the boost pressure. I also tried on a mountain road and it also displayed 120 kPa.
When not on the gas pedal, it showed 24kPa (3.28PSI, 0.24bar).