Ok, so how do you "load" the new modified flightplan?

Badly written on my part. Yes, I do open flightplanner - then click "load" and then instantly go to the cockpit. I never check the flightplan itself in flightplanner, that's what I meant.

BTW, I had a flightplan refusing to load during the weekend. It might have been related to a blank space after the last , in one line. Seems minor but I had to rewrite it almost completely then it magically worked again.