Young rabbits need unlimited pellets and hay to grow properly. I found that as my baby rabbits got older I slowly had to eliminate the alfalfa in their diets to avoid soft poop.
Here’s what I did with my baby rabbits:
1. They were eating alfalfa hay and alfalfa pellets but I was finding a lot of mushy poos mixed in with their normal ones.
2. I switched from alfalfa hay to orchard hay and kept them on the alfalfa pellets. This was alright for a while but as they grew I was noticing some more soft poop.
3. I switched them from alfalfa pellets to a timothy hay based pellets. Still fed in unlimited quantities + orchard hay that’s what they’re eating right now with no issues.
My advice would be to switch to a non alfalfa hay if you’re feeding any alfalfa hay. If you take away the alfalfa hay and you’re still noticing soft poo then I would switch to a timothy pellet. Switching pellets is a slow process that can take about 3 weeks or so. I believe someone posted the mixture ratios on one of your previous threads about this.