I'd love to have an opinion here, actually, I do, but it's not too helpful. I'm very suspicious of problems that "fix themselves". I think you might experience it again sometime in the future, but until you do, I can't see anything that will help prevent it.
I really liked Bill's opinion that it had to do with shift points or torque reduction. (Of course, why wouldn't I? He's the expert!).
And, I would have tried the, "Lower the 3-2 shift point at WOT to eliminate going from 4 to 2 on the downshift." approach.
- Jack
__________________
2024 F150 Platinum SCrew 3.5L PowerBoost FX4, Peragon Tonneau Cover, LineX Bed, 35% Window Tint on All Sides and Rear, Full Nose Paint Protection Film, Husky Mud Guards, Lasfit Floor Liners, VIOFO Dash Cam