Yes this is the rabbit with the breeder issue. I’m not sure if he allowed to stay the full three weeks but make sure to have a syrange with some KMR kitten formula if your don’t see your bunny eating you can get it at Wal-Mart or any pet store. My local shelter also mixes a small bit of heavy whipping cream to entice bunny to drink and make sure it’s a little warmer than touch temp.
Your bunny will also be very scared on the first day some bunnies are explorers but from your avatar if that’s the most recent picture I would show signs for concern if not weaned right.
You doing everything right just go slow and try not to handle unless it’s a must like to move to a cage or from kennel. Introduce small amounts of space before increasing the area during play time
This is my emergency notebook giving by my vet regarding kmr milk feeding that I help others near me with only use this if you don’t see your bunny eating hay or pellets at all he might not be weaned properly (also ensure that water and pellet/hay are easy to reach on floor using a tupaware lid) only use this information as a reference JUST IN CASE your new baby does not start eating. I would also try to see if you can schedule a vet visit to ensure proper health and give detailed info to your vet about the breeder issue.
Formula recommended KMR Kitten formula (warmed to body temp)
Newborn – 1 week
4-5 cc formula
1-2 weeks
10-15 cc formula
2-3 weeks
15-30 cc formula
3-6 weeks, until weaned
30 cc formula
Baby rabbits feed from their mothers while lying on their backs. You may loosely wrap baby in a soft face cloth or hand towel and lay it on your lap or in the crook of your arm. If bunny will NOT eat this way, of course, do the best you can. It is ABSOLUTELY CRUCIAL to let the baby eat at it’s own pace—especially if it is not suckling from the syringe willingly. If you squirt the liquid in too quickly you can aspirate (get liquid in) the lungs and the rabbit will suffocate