I have the opposite issue, Harley loves his veggies but Thumper is fairly lukewarm about them and won’t touch them if I’m in the room.

Bunnies can have their preferences. Bunston used to snub his greens if they were wet, which was annoying, as it is good to feed wet greens to get more water into them.

If this is a sudden change, I would suspect a health issue, dental or otherwise. But if he is otherwise eating and pooping well, he may just be a bit picky. he may be tired of those specific veggies, so it might help to rotate what they are getting each week.

With Bunston, I found it helped to only feed one green type at a time over the course of the morning (in order of least favorite to most). If I put all the salad out, he would only eat his favorites, then Bertha would eat all the rest. So, I had to feed the romaine first, then the kale, then the cilantro, etc.