I blame Northern Tool for everything. When it rains.. when my dog won't go out in the rain. Everything. Not a fan, but I'll get off my soap box..
I ran into the same issue when I was using a smaller pressure washer. You have to do small sections at a time and keep the water moving.
Surface cleaner. Sweep with the nozzle. Surface cleaner. Sweep with the nozzle. Especially when it's sunny and hot and the driveway is drying behind you. I keep a big push broom in the truck for when dirty water washes back into low spots to keep things moving.
Bigger surface cleaner, bigger pressure washer, and always moving downhill helps a lot. Do it enough times and you'll start knocking out driveways in 30 minutes.