I have thought for some time is it possible the TX pumps were never switched on in the first place. The reason is, it makes a little more sense never having turned them on than turning them on at start up and then turning them off for some reason somewhere before 76kg in the main tanks and not switching them back on again.
Why would the TX pumps ever be turned off before pump cautions which happen a lot later than 76kg in the main tank? (At 19kg and 18kg from Sid's post.)