EFOB is not accurate

[lolo]

Hi, 

From VHHH to KJFK, after 12 hours of flight, my EFOB is absolutely inacurrate. It's showing 36.8T for EFOB at every waypoint, for a total of 36.3T at destination, with a remaining of 1872nm to fly. Earlier, I realized that the LNAV stopped working. My plane was not flying to the next waypoint. Is this causing an issue in fuel calculations? I think the systems should adjust the EFOB when the plane is back on LNAV.

Laurent,