My bunny has “thrown up” post pellets before as well, the vet assured me that bunnies can’t actually throw up which is why it comes out their nose like a sneeze - he just ate the pellets too quickly, maybe mix in more greens with the pellets so he can’t inhale them all at once and choke...
Meet my bun babies Stitch and Posie! Both rescues from the local shelter, posie is an American, 4 in October and stitch is a Dutch mix a little over a year old .. they are absolute snugglebugs, free roaming and just finished bonding!