747 LNAV problem

When I create or load a flight plan, until I engage the LNAV, I would pass one of the nearest waypoint
After i pass it, it doesn’t pass to the next one and shows it as target. HDG hold remains active untill I bring back the plane to that very first waypoint.
And even it catches that waypoint after i arrive back, if the next turn is tight, loses the track again and goes straight even showing that waypoint

I am experiencing exactly this problem on then 787. LNAV does not seem to pick up the flight plan after a certin waypoint. I have resorted to a long haul flight adjusting the heading to follow the magenta line.