Horses aren't "brats." They can buck for many reasons: excitement, pain, frustration, etc.

My horse is a bucker. He bucks when he gets very excited (first outdoor ride in spring, after a big jump when he hasn't jumped in a while) but hes also bucked due to saddle issues and frustration (when Im not being clear with aids or he doesn't understand what I'm asking).

To ride through it (which really is only effective if it's excitement), you've got to work them harder/distract them. Lateral work, transitions, smaller figures. I also teach my horses one rein stops if it's an emergency.

Id check for saddle issues and any pain as well, especially if it isn't a normal thing.

Id also examine what you were working on. Was it a frustrating ride? Was it something new? Was he a bit off otherwise? Etc.

Best of luck!