I think the explanation is this:

The NEDC was replaced by the test procedure according to WLTP (Worldwide harmonised Light-duty vehicles). This also applies to vehicles in category M (passenger cars).

The new test procedure has been in force since 1.9.2018.

I do not know how this will affect vehicles approved before this date.

A serious discussion with the dealer seems appropriate to me (delivered vehicle does not correspond to the data, which were basis for the order).