Try to find things for him to jump, that have no lower parts he can use. A shopping cart has no bottom for him to jump lazy on.

Bulldogs spend 95% of their lives seeing how lazy they can be. Our goal is that when ANY words come out of your mouth, IT IS 5% TIME! This is why you must pump him with emotion, and keep it FUN! Go to an amusement park and sit in the parking lot. Watch the kid's parents struggle to control their children, from the second they get out of the car, all the way to the front gate. That is the goal for our dog to act like, ANY AND EVERY TIME WE SPEAK.

He will damn sure give you lazy, if you give him the chance. The reason he jumped on the bale from the side, is because he could do minimal effort, and still make you happy. Bed of a truck has no bottom. We want to make his minimal effort habit, to clear the top of his jump. I hate this explanation, I gave here. I hope you get my drift. Maybe someone can better explain our goals here. The habit to always clear the top, is our next goal, with a Bulldog. You already have him happy to leave the ground. That goes against his natural tendencies.

Don't worry about height for now, worry about creating a habit.

https://www.youtube.com/watch?v=b3CjNO1Fd_4