A horse certainly can buck on landing due to front foot pain. I had a lease horse teach me this the hard way. He had big feet but turns out needed to have them left a bit longer. Or he’d be a little foot sore, apparently. He was a nice mover, and it was nothing obvious, but one day landing off a large oxer after he got trimmed, I could’ve earned myself a shiny belt buckle.
The balling up feeling is not excitement in a way humans would use the term. That’s anxiety. I’ve known lame horses who are happy enough to jump in that they won’t just refuse the jumps, but they’ll let you know about some discomfort on the back side. And they will get anxious. For example, a horse with stifle or hock issues might jump fine but be worried about the lead change he might need after. That starts manifesting as anxiety to and after the jump and possibly landing and bucking.
This has been going on for a long time with this horse. Just because your vet didn’t find something your vet thinks is serious doesn’t mean the horse does not have pain that horse thinks is serious.
I absolutely would stop jumping this horse.