Hard to say PGA.
You have over 500 ranked rounds and I think your driving number is about 78% so it would take a lot to move it much.
500 ranked rounds assuming 7 driving holes per round is 3,500 drives. So if you are at 78% that would mean you have hit 2,730 of the 3,500 fairways. If you had a round in which you went 7 for 7, then you would go to 2,737 of 3,507 or 78.04%. If you went 5 of 7 then you would be at 77.87% so it doesn't move much but what you mentioned doesn't make much sense. Getting all of them should make your % go up, even if it is slightly.
I'm not positive how quickly WGT posts the stats from each round so it might be that the number you see has several rounds in it. I'll just be happy when we get a stat board from WGT that shows all the stats from all our players, think that would be cool.