Further info on FMC progress page, if you can determine if it's the Totaliser system or the Fuel Flow Transmitter system you can inhibit their input into calculations as per the instructions highlighted below.
Progress Page 2/2 is accessed by pressing NEXT PAGE key when on
Progress Page 1/2.
Data Fields
1L-1R WIND COMPONENTS/WIND VECTOR
2L XTK ERROR - Displays current cross track error.
3L-3R TAS/SAT - Displays current true airspeed and static air
temperature.
5L Blank unless there is a 1360 kg discrepancy between the totalizer
and calculated fuel values. If a discrepancy occurs, the line select
fields are formatted as shown. Line selection causes the system to
use the fuel totalizer input and inhibits the calculation of fuel used
based on fuel flow. Line 6R, CALCULATED FUEL, blanks if 5L is
selected.
2R VTK ERROR - Displays current vertical track error with respect
to a path descent. (Blank when descent not active.)
5R Same as 5L except that selection causes the system to use the
calculated fuel and inhibits the totalizer input. Line 6L, TOTALIZER
FUEL, blanks if 5R is selected.
6L-6R Manual entry of fuel quantity on the PERF INIT page is
propagated to line 6R and is the initial value of fuel quantity used.
Line 6L is blank and subsequent totalizer inputs are ignored.