It is correct for a younger rabbit to be on a more alfalfa-rich diet (both hay and pellets), but in a number of cases, this is ramped down earlier than 6mo because the alfalfa is too nutrient-rich, thus leading to the production of cecotropes that are not eaten. It’s most likely the double-combo of alfalfa pellets and alfalfa hay that’s making this occur (check the ingredients on the pellets).
I’d recommend swapping the alfalfa hay back for what you had previously. Leaving veggies out is still good for his young stomach. Young rabbits need nutrient-dense diets to help them grow rapidly, but if you see those excess cecotropes, it means your rabbit is getting too much, so it’s okay to make the swaps as needed.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.