It is human nature and takes practice not to apply more on the horizontal surfaces so the hood is a common place for too much material which can cause problems like you have.
If the doors are the only things peeling, and the hood is the only place that did that, you have to think what was different with THOSE parts primer and paint application? Let's say the whole truck is peeling but the tail gate, yet they were all sanded with 600, you can eliminate that as the reason, if the whole truck was painted at once, but the tail gate was done the next day after you sanded it the morning of, that can tell you that the wait after sanding on the truck is the problem. If the tailgate was sprayed in a different temp, that could be the reason it worked and the rest didn't.
Toss out all your preconceved thoughts blaming something and study it to see WHAT WAS DIFFERENT about the panels that are failing? Why is the hood different than other panels? THESE are the questions you need to ask yourself.