Fuel prediction page displays actual GW

Load the aircraft empty:

Next, enter an incorrect ZFW of 130 tons on the INIT B page. The aircraft calculates a GW of 184 tons as expected:

Start an engine and go to the fuel prediction page. It will now show the actual GW of 143.5 tons:

Since the aircraft cannot know the actual ZFW, I would expect it to display 184 tons.